I REALLY NEED SUPPORT RIGHT NOW. I know it's long but plz still read.

I'd consider myself to be usually really good. I'm almost 16 and I'd never done anything really bad until now. I hadn't even kissed anyone before last night. But my best friend who also happens to be a boy surprised me at my house. I moved to a different state so I hadn't seen him in person for 8 months and I was really excited to see him. We watched a movie until like 1am and I don't know... It was just different between us. We ended up having sex. I don't even know how. I haven't done anything before and now I'm not even a virgin. I really don't need to be called names right now. I just need some support. The weird part is that it was good and if I had to do it with anyone it would be with him. Did I make a mistake?