Burning Sensation in Chest & Story

To give some context on my situation, I went through a really bad withdrawal from venlafaxine/duloxetine a few years ago. I've been picking up the pieces ever since, but it seems like every time I pick some up, more fall off at the same rate. Anyway, prior to my withdrawal, I had this almost constant feeling of anxiety in my chest. Just this tight, anxious, uncomfortable feeling that was always there. During my withdrawal, I had been prescribed Vyvanse, which I started taking, but it was making my anxiety worse. At one point, during a period of extremely heightened distress, it was like something just switched in my brain or body. I suddenly started experiencing this intense burning sensation right in the centre of my chest. It starts around my sternum and radiates outward into my pectoral muscles. The worse it gets, the further it spreads. Ever since that day, I've experienced varying levels of this burning sensation. It's usually with me every day, sometimes worse than others, but almost always causing a lot of discomfort. It's almost like that constant anxious, tight feeling I used to have was replaced by burning instead. Initially, I thought maybe it was heartburn, but antacids don't seem to help. This has been going on for almost three years now, and it wasn't until recently that the burning almost completely disappeared. Without going off on another tangent, I'll try to give the Coles Notes version of what happened. I've been taking 300mg of venlafaxine for roughly the last two years. During that time, I would get really bad brain zaps starting about 3–4 hours after taking my dose. I never missed a dose and usually took it within a 30-minute window, give or take. Most days, the brain zaps were so severe I'd feel them shoot through my entire body, right down into my feet. I'm sure most people here are familiar with them. For me, they happen whenever I move my eyes left or right. I'd usually get three or four in quick succession, and they'd start a few hours after taking my medication, getting progressively worse throughout the day. On top of this, I noticed my mood would drop off pretty significantly around the same time every day. A couple of months ago, I had a particularly bad week. My brain zaps were absolutely horrendous, to the point where it felt like I was going through withdrawal again, despite taking my medication exactly as prescribed. My mental state was also deteriorating really quickly. I was spiralling, catastrophizing, and my thoughts were escalating into suicidal ideation. I was becoming increasingly scared and isolated. These kinds of intense mood swings and completely uncontrollable thoughts were never something I experienced before SNRIs. That episode really made me stop and think about what was happening. I started reading up on what could be causing all of this, and everything kept pointing toward interdose withdrawal. I couldn't understand why else I'd be getting such horrible brain zaps while taking my medication consistently. At first, I wondered if maybe the pharmacy had switched generics, or if I'd gotten a bad batch. But the thing is, I'd been experiencing the mood issues, depressive episodes, and brain zaps for almost two years. This particular episode was just so bad that it made me question everything. Anyway, I ended up doing a pharmacogenetic test to see how I metabolize psychiatric medications. Turns out I'm an intermediate metabolizer of venlafaxine, and it was one of only four medications on the report that they recommended doctors avoid prescribing me. On top of that, I'm an ultrarapid metabolizer through the secondary enzyme involved in processing venlafaxine's active metabolite, desvenlafaxine. Apparently, that secondary pathway isn't considered as important, but the combination seems to create a strange metabolic situation for me. I know these tests aren't an exact science, but the fact that ive been dealing with weird withdrawl symptoms while taking my meds and the report notnrecommending it can't be a coincidence. After learning this, I started splitting my venlafaxine dose into twice daily dosing, and things actually started improving. My mood became noticeably more stable, and the brain zaps got significantly better, although they never completely went away. But I've also been dealing with a ridiculous number of side effects. I've struggled with insomnia for over a decade, but I also experience myoclonic movements in my arms, legs, fingers, and hands, extremely dry mouth, nose, and throat, and the palms of my hands have become incredibly sensitive. I also get these weird pins and needles sensations in my fingertips, especially my thumbs. And the list goes on. This could also be pregabalin (600mg), mietazapine 15mg and dexedrine 60mg that I take, ontop of the 300mg of venlafaxine. Its a lot. Because of all this, I decided I wanted to start reducing my dose. I was finally feeling more stable, but I couldn't stand the side effects anymore. I also started questioning whether the mood swings and depressive episodes I'd been dealing with for years might actually have been caused, or at least made worse, by the medication itself. I said I was going to give the Coles Notes version, but apparently I've written a whole story. Anyway, I recently started tapering venlafaxine, with the intention of following a hyperbolic taper. My first reduction was actually a full 37.5mg. Based on what I'd read about receptor occupancy at higher doses, I figured this reduction shouldn't be too disruptive. And surprisingly, it wasn't. I had some increased brain zaps and felt a bit more "raw," which is how I tend to describe that overly sensitive feeling. But after about three or four days, things settled down. So I thought, great. Maybe I can do another 37.5mg reduction, get down to 225mg, and then figure out a more gradual tapering plan from there. Part of my thinking was to potentially cross taper to Pristiq, since desvenlafaxine doesn't rely on the same liver enzymes to the same extent and would bypass my metabolic issues. On paper, it seemed like it might provide a more consistent effect. Although I know Pristiq can be more difficult to taper because of its tablet formulation, and there's no guarantee that pristiq will even help, or make things better. But anyway, that's another tangent. What I'm really trying to get at is that I couldn't tolerate that second 37.5mg reduction. The burning sensation in my chest came back pretty intensely, and I generally felt awful that day. I ended up going back to my previous dose, and things improved again. I figured I'd have to start making much smaller, hyperbolic reductions earlier than I'd anticipated. So that's what I'm doing now. I counted the beads in a handful of 37.5mg capsules, calculated an average, and made a reduction of roughly 10% of the beads in one capsule. And now that familiar burning sensation in my chest is coming back again. It's incredibly discouraging because it felt like it had started to finally go away after years. Part of me worries that something in my nervous system was somehow altered by my withdrawl experience. I don't know if that's actually what happened, but it's hard not to wonder when the exact same physical sensation keeps returning. What makes this especially frustrating is that, after nearly three years of dealing with this burning sensation almost every day, it had finally started to disappear. For the first time in a long time, I actually felt pretty stable. Mentally, I was doing well. I felt good, aside from all the side effects and other health issues I've been dealing with. And now, as soon as I try to reduce my medication, that same burning starts coming back. It's making me worry that I won't be able to taper without bringing back the horrible anxiety and potentially the depression that I've spent years trying to get away from. But I'm also really worried about how long this burning sensation is going to last. Is it just a temporary thing while my brain and body adjust to even this tiny reduction? Will it settle down after a few days? A few weeks? A month? Or is this something that's just not going to go away? That's what scares me the most. I've been dealing with this burning for almost three years, and it was only recently that it finally started to almost completely disappear. I was finally getting some relief from something that's caused me so much discomfort for so long, and now it's coming back from such a small reduction. And when I say burning, I mean actual burning. Sometimes it gets so uncomfortable that I find myself constantly rubbing my chest, trying to get some relief. I'll rub it so much that I end up leaving red friction burns up and down my chest, and then my skin gets sore on top of the burning sensation I'm already dealing with. It's like I'm trying to rub away a feeling that's coming from somewhere underneath my skin. I noticed that when it started going away after splitting my dose, is that the muscles in my right pectoral would feel like they were like kinda twitching, like this weird movement. It just felt sorta weird, not uncomfortable or any real discomfort. Its like the muscles were not reacting as strongly and they spasm instead of causing the burning. The spasm went away and the burning was gone too. I think part of what worries me is that my nervous system was somehow damaged or altered by that severe withdrawal experience, and now I'm stuck needing these high doses of medication just to feel somewhat normal. I don't know if that's actually possible or what's happening, but after everything I've been through, it's hard not to think about it. I also can't help but wonder whether some of the anxiety, mood swings, and depressive episodes I've experienced over the last few years have actually been related to the medication itself, or the way my body metabolizes it. Especially considering how much more stable I became after splitting my dose. And that's what makes this whole situation so frustrating. I finally started feeling better mentally, but I'm dealing with so many side effects that I really don't want to stay on these doses forever. Yet when I try to reduce, even by a tiny amount, I start feeling that same horrible burning sensation again. I know I've written a lot here, but I wanted to explain the background because I feel like it's all connected somehow. What I'm really wondering is whether anyone else has experienced this kind of intense burning sensation in their chest? Did it ever stop, what did you do? What helped? For me, it starts right around my sternum and spreads outward across my chest into my pectoral muscles. Sometimes it's really intense, other times it's just this constant low-level burning that's always there in the background. It's not heartburn, at least antacids don't seem to do anything for it, and it feels different from the anxiety I used to experience before my withdrawal. It's almost like the way my body physically experiences anxiety changed after going through that severe withdrawal, and I've never really understood why. If anyone has experienced something similar, did it eventually settle down as your body adjusted to the reduction? And if so, how long did it take? Days, weeks, months? I'm just really worried that this is going to be another long term thing, especially after finally getting to a point where it was almost gone. Cool As a Cucumber