Weird disease? PLEASE HELP!!!!!!!!!?!

Weird disease? PLEASE HELP!!!!!!!!!?

okay, all of the sudden i have been getting sick whenever i eat something greasy, fatty, or just plain not healthy. i havnt really been paying real attention to it untill my friend told me she has something SUSPICIOUSLY SIMILAR to it and it started right after i spent the night at her house. neither of us hav any eating disorder and we're both 13. [[in case that matters]] Pretty much the only thing i can eat is salad[[WITH OUT THE DRESSING!]] without getting sick. its really starting to drive me crazy. like, last nite i ate 1 oreo and a couple of cashews[[long story]] and i was sick all night. is something wrong with me? this has never happened before, so i dont kno. the only thing i can eat without feeling sick to my stomache is a salad with no dressing and a glass of water. [[NOT EVEN JUICE!!!]]. what should i do? how do i fix this? please help! and thankyou!!!!!

2 weeks ago
oh, and im a girl incase that matters

gastritis