What could be the reason why I feel nauseated after I eat?

About 85% the meals I eat end up making me feel nauseated after I am done. I don’t over eat. The meals I have noticed that do not make me ill are basic things like eggs or oatmeal, but everything else makes me feel like vomiting up to a few hourse after I have eaten.

Yes, I could go to my doctor, but she is a total bitch and I need a new doc, which I don’t really have the time to do.