what's wrong with me?!

Saigelynn • i play guiar and uke, sometimes i sing
About 3 weeks ago I had the GI bug bad. I passed out 3 times and threw up whenever I'd wake up. I went to the hospital and they said it was no big deal, just a seasonal stomach bug. About a week later I was feeling fine, but couldn't eat a lot like I used too. I'm about 114lb and people think I starve myself (which i don't). I've been skinny all my life (just a high metabolism). *picture down below* 
But whenever I eat,my stomach hurts and I get motion sickness and a little nausea. 
If anyone knows what this means please send your advice! (My family as history of stomach problems. Mainly my sisters and my mom after her C Section)