Help me!!!

I really just need advice. I had sex w/ this guy that i really didn’t want to, but i didn’t stop him. Why? Idk. When i said i just wanted to chill he began to push to offer of sex more. He did ask me if this is ok but i never responded and continued to engage in the sexual act even though i didn’t want to. At the time it seemed easier to just continue instead of explaining why u don’t want to... I’m in college and people just have causal sex all the time.. i tried it and don’t really care for it i lose interest so much faster when i do. i think that I am struggling with the fact I didn't speak up. I've been crying and worried all night and having really bad anxiety. Why when u what to hang out with a male they always want to have sex? I'm really aggravated and disgusted with myself and him.