firstly.
it wasnt such a bad idea, your first trip should be a life changer and the general weakness of blotters these days means IMO two or possibly 3 or 4 would be what most old timers would call a trip
so dont beat yourself up about it, if you made it through with out doing something embarassing like calling an ambulance give your self a pat on the back
terrance mckenna said "if it doesnt feel like you've taken too much then you haven't taken enough"
Bad news is if your first trip is bad some of the anxiety may cloud other future trips, should you wish to try again.
but remember tripping is not for everyone and if your one of the many people who cant let go and enjoy then its no big deal, its not the be-all-end-all of life or drugs
as for the stomache issues...usually acid leaves me without any physical side effects, although sometimes i feel a little queasy and have a greasy feeling on my skin.
this should pass within a few hours.
sounds to me like you need to sleep, eat as much as you can and stop worrying about it. You probably didnt eat when tripping so your stomache has shrunk, it only takes a day to shrink it, but it can be hard work and an effort to get it back to normal.
i would hazard a guess that its being made worse by anxiety...as its bothered you enough to post.
you havent damged yourself
if you had any visuals during the trip i imagine it wont be long before, even though it was tough at the time, you find yourself glad that you experienced it