Yeah, from researching and reading books over the years, one thing that always comes up is if you think there is something physical go and get checked out. Most of the time there isn't, it's all in the head, but at least it rules things out and can give you some peace of mind.
Hangovers are definitely the worst when it comes to panic attacks. If I was badly hungover I would have to avoid doing anything. Some of my worst experiences came simply standing in queues at the Post Office, bank or even just shopping. It would bring on a full blown panic attack, where I would have to leave and just walk anywhere until my heart slowed down and my body stopped shaking. Fucking terrifying stuff! Travelling by bus, train or plane would be completely out of the question so I can't even imagine how that plane journey must have been like for you!
It's good that you've cut back on the drink and caffeine, I gave up coffee years ago as much as I enjoyed it. Still drink a good bit, but I just make sure I'm not madly hungover if I have to travel or do anything important. And because of Dare I can handle those situations I struggled with before, even with a bit of a hangover.
And I would also suggest not Googling anything when it comes to symptoms etc, I've been there before and it made things worse because you get all sorts of contradictions, and can leave you even more confused and anxious.
Try not to worry too much about any of it mate, if there is stomach issues you'll get that sorted, and the mental issues will take care of themselves, you'll be fine :35: