This going to be a little bit of complicated answer but your case sounds serious and so it is worth the effort.
It is said that there are things which occur to us in our heavens so to speak or in our relationships with our relatives as an example way before those then get ‘transposed’ onto our physical 3 dimensional realities. These can be good things as well as bad. So it might be something snaps in our relationships and later on we get it as stroke, something snaps, bang all your marbles roll all over the floor and you can not longer put together those strings (attached – pun intended) which held your marbles in that order, you have to reinvent a new structure for them, which may be difficult in your old days. Some people cannot have a stroke though they have had a similar snap in their heavens and they cannot sort of like act it out in real life, because they would not survive it, and in those instances nature or fate or the universe chooses a kinder version and the person in question is just a little doo-laly instead of having a full blown stroke, because those strings have snapped in heavens , it just cannot materialise in real 3 dimensional bodily life. Having a stroke enables you to fix the problem you have in heavens not having a stroke diverts you til the day you die from solving the snap problem. It does not say a=everybody should have a stroke, but if you have had a heavenly snap, it is best it is acted out, if our body mind spirit support strictures, relationship is considered strong enough to catch you.
Now it is possible those things or that one occasion which was like a big heart palpitation in heavens like a shock horror you might have received in your daily goings on, has its first chance to be acted out to materialise in your 3 dimensional bodily life and I can believe they might even be excruciatingly painful, but there is nothing you can do about that particular life event that is causing these (other than finding which one it was and then making steps of making that more comfortable – maybe I’m only wild guessing it might have been a betrayal or some deeply hurtful lies which caused some kind of an exasperation in your spirit realm and your microcosm has been waiting for an opportunity to have these ‘done’ now properly because sometimes you can’t hold on to having these hanging over you for ever, they have had to happen and yes they happened as you became a vegan – congratulations in order actually – because your spirit sees your body strong now to cope with those storms so acts them out. Some people suffer hair loss when they turn vegan as a result of some sickness related process their body had already started before they turned vegan and becoming vegan fought off the real harm, but some side effects of the harm actually relieved remain – like hair loss and some seek cures for the hair loss, about which there is not that much you can do, although it is good you are seeking solutions to something it is just not that good you are seeking solutions to some indicators to some danger that which now has retreated.
and then you do know that time was spent in vain – sort of and I was wondering if the palpitations in your case are similar the after effects of some big baddie whooshed away that has just left a few side effects like heart tremors for you to cope with.
Mainstream medicine will not know the questions to ask never mind the answers and yes they may be able to advise on whether to take iron supplements or as the previous person suggested olive oil for palpitations in general as there are things which smooth the feeling itself, but to find the real cause, which you can then deal with I suggest you talk to some vegans because we all have these inclinations about health facts and truths and dare not speak them because the medical profession has rejected every argument we’ve come up with other than we just feel it is that way, but often you find if the sharing of the truth is with the intentions of saving somebody we are more forthcoming with our often invaluable facts of vegan scientific observation.
Good luck in any case and most certainly persevere, being a vegan is much more healthy than eating meat in more ways than one, so keep up the good intentions. If you revert back to meat eating your palpitations cannot materialise and cannot be dealt with.