idk what i have ... but i have something

I feel like i have a small stomache , i can’t eat a lot which is becoming an issue because i want to gain weight. Also Everytime i eat i sometimes want to gag and throw up, idk if its from me having anxiety or me having acid reflux? I think i have something stuck inside me and i can’t eat like a normal human being. I been dealing with this since high school and i’m 23 . I don’t have bulimia or anorxia none of that. Ugh i just want to eat normal without gagging.