I am partly like you, in that I feel like vomiting (but do not vomit) and cannot physically eat and sometimes even drink liquids when under extreme stress.

It looks like typical anxiety. I have it easier than you do because I experience it in a much limited set of circumstances.

It has nothing to do with being unhealthy or not eating right - I eat a perfect die at and I still get those spells, from time to time.

The additional things you describe - shakiness, tightness in your chest, etc. - are all consistent with garden variety anxiety as well.

There is a forum on Anxiety (I do not know the URL because I have blocked it from view but it is under "Mental Health Support") and you should browse it and perhaps post on it in addition to getting support on this thread. You will see that your misery does have company - you are not alone in it. Your concern is not random, nor is it strange.

You probably need professional help with it, because it affects daily functioning, forming relationships, social contacts, etc. I just live with it because it does not affect me as deeply as it affects you - I know that from time to time I would feel like vomiting and that it would then go away, so I have stopped worrying about it.

If you cannot drink liquids when you feel like vomiting, that by itself would create a problem, because you would become dehydrated, and dehydration is harmful and will exacerbate all the things you are experiencing. Can you / can you not drink liquids during those spells?