Hey, I'm your brother, there's nothing you can't tell me. And I'm glad I know.
You're not in any danger from sleeping with someone. Feeling guilty and worried about it isn't strange, though, trust me. But you're going to be okay. I'm a little more worried about you being drunk enough that you went home with a stranger and don't remember any of it. That doesn't happen a lot, does it? That much drinking, I mean, not sex.