I feel stupid!!!!

So I am an 18 year old girl who lost her virginity about a month ago. It was a very bad experience, he was drunk, it was at 2 am, and he passed out right after. I seemed to get over that and everything was going very well. But then he tells me that he is back with his ex gf. I haven't talked to him in about two weeks but I see him in my classes. Lately I have been thinking about him a lot and I really miss him. He and I have started talking again and I still really want to date him. I don't think that his ex and him lasted, and he has been flirting. Is it stupid that I can't stop thinking about him? All I want to do is tell him that I miss him!!