Holy shit, this sounds exactly like me. In my case, I fell backwards out of the shower, but all the same feelings/symptoms. Likewise, doctors are convinced it's not cardiovascular, and MRIs have shown nothing in my cervical spine (which is where I figured the problem would be). Taking Prilosec has had a substantial effect, though things aren't perfect yet; this comment really encourages me to keep taking it and hope for the best!
I had food poisoning. The vomiting caused damage, and I had many similar symptoms. Some of them led to panic attacks. Needless to say, I had poor results with Doctors, and ended up on a pretty strict diet for about 2 years which helped reduce acid. Things are much better now, but I notice that the symptoms are also linked to my mood. If I'm feeling down/sad, everything flares up again.
When I read about his condition, it helped point me in the direction that it might be esophageal spasms.
I remember it was like living in constant terror for the time it was an issue. Even if you try to tell yourself it's not heart related, that you aren't going to randomly suffer a heart attack, everything from the vagus nerve is telling you that it's your heart.
I saw immediate relief from taking the Pepcid max strength product, but initially the relief would only last for six hours, then I'd get chest pains again. So I had to take three or four per day at first. How often I had to take it, decreased by the month roughly.
I cut out all caffeine / stimulants of any sort. I avoided all hot liquids, and all sharp foods that could catch on my esophagus tissue (I was assuming it was getting constantly re-injured, or that potential new scar tissue was very sensitive). Caffeine was making it quite a bit worse. Accelerating my heart would trigger it a lot. I was also having intense problems while trying to sleep, I couldn't lay down at night normally, which again led me to think it was my heart (I felt better sleeping upright). The vagus nerve would get triggered in the middle of sleeping, and it'd cause a big jolt of pain across my chest and wake me up.
I'd suggest those things: no caffeine, no hot liquids, be careful about stimulating your heart (as it might act as an esophageal and vagus nerve trigger), something like pepcid or prilosec (take as much as you need to get it to stop while staying within reasonably safe limits of dose), limit sharp edged foods (really just avoid aggravating the esophagus). Maybe those things will help you heal too (if it's a similar root cause). The biggest thing in my opinion, is you have to figuring out a way to buy your body a window of time where there is little to no re-injury or high level agitation, so it can heal itself.
