How to know if you were sexually assaulted

Okay so basically this is about my first time which I had mixed feelings about. It was a guy I had been talking to for months and he was finally coming to see me. I had told him a few days before that I was actually a virgin and didn’t feel comfortable losing it with someone I’m not in a relationship with. He said he understood. We agreed only oral if it came to that. Long story short I’m thinking I’m bout to get head he’s undressing but he basically slides in. I was too nervous and kinda scared to say no. Plus he came hours away to visit me. So I didn’t say anything. I was very confused after that. We still hookup sometimes because I don’t want to do that with anyone else rn. What should I do? Because every time we don’t speak a lot I find myself getting angry about the first time all over again. But when we are good, it’s like I don’t notice it. What’s wrong with me