Decreased appetite/upset stomach

I threw up twice on Monday night. Since then I been been nauseous and when I do eat, it’s anyones guess whether I’ll be in the fetal position afterwords. Although I do see a correlation between my stomach upset and tomatoes and sugar. Thinking maybe I have an ulcer…?

My question is: I haven’t been eating as much as I normally do because of said problem so could that affect my supply? My baby girl is 7 months old. I am just always worried she will be hungry. My letdown has been taking longer to occur as well. I’m assuming that’s stress related.