Food problem

Hi /sci, I have a problem with food. I can only eat some 8 dishes I like, and I would very much like to be able to eat anything because it's a big problem for trips and work. However, the second I take a bite of anything else, I almost throw up. It's not that I don't want to make the effort of eating something I don't find delicious - it's that if I take this effort, I feel like puking and can't get past the first bite. Do you know anything about this kind of problem?

first, what medical problems do you have?