I know only too well how chronic gastric issues can make life miserable.

So let me ask you some questions (for your own self-reflection):

How's your home life? Are you at peace?
Do you have a good social circle? Some friends, buddies, etc.?
Anything happen two years ago that has a lasting effect? A romantic breakup, other big emotional loss?
I see you're 18. Are you stressed about starting college?
Are you getting enough exercise? Please tell me you aren't spending all your time staring at a phone.
How's your diet? Garbage in, garbage out. You can get away with a lot when you're young, but you'll pay for it later. (I should know.)
What do you do for fun? What are your hobbies?
Having a sense of purpose is important. What are you doing to improve the lives of people around you?

The mind can play havoc with the body. I bet that if you increase the peace in your life, you'll feel better.

Just so you know, I became permanently disabled more than seven years ago. I'm not letting it stop me; I'm using my experiences to reach out to help others via YouTube:
"From Recovery to Discovery": http://www.youtube.com/@srlucado/videos