What's my problem caused by Chronic Nausea/Vomiting?

[LostBoy121]

A little over a year ago I started getting chronic nausea. When it first started I was eating Taco Bell and was quickly running to class but I was nauseous so I went to the bathroom first. I then threw up and went to class feeling horribly but the feeling passed after about 20 minutes. After class I thought it was just food poisoning and didn't think much of it. Yet, the nausea kept on coming only when and after I eat/drink. In addition, there was pain in my lower right abdominal area that would take hours to pass. Weeks went by and I went to 3 different doctors. They tell me that they can't find anything in my blood through a CT scan. I thought it was a link to my past acne medication, Claravis (Isotretinoin) but they told me since the symptoms started showing up 4 months after stopping Claravis that it's probably not caused by this.

Today, my nausea isn't as bad as before but is still a major problem since I go throughout my day not eating very much since I fear puking in my classes. In addition, if I get super nervous about presenting a project/take a test that I get nausea as well. This is unlike me and feel un-normal because I get very dehydrated and loss my appetite for food even though my stomach growls.

Thank you for reading and if you know of anything that could help me please let me know!