Someone please tell me if I’m wrong??

So I had sex with my baby daddy on Sunday night then on Monday I started feeling a stinging pain when I pee so yesterday I decided to check what’s wrong I had small sores in my uretha. So last night I decided to ask him if his cheating because it could be an STI n his my only partner so now he is very upset at me telling me I don’t trust him n he can’t be with someone who doesn’t trust him so we must reconsider the relationship. Guys was I wrong to ask? I’m also scared for my health