If you don't know what to talk to someone about, then you don't love them.
You're right; you're obsessing. This sort of behavior is a way to ignore your real life and the friends - including boys - you could be spending time with and getting to know now, and in person.
It's called avoidance behavior.
We all do it, but recognize it for what it's worth. It's a fantasy escape from your day to day existence.
Start by spending time with your in-person friends more. Study together. Get sodas or coffee as appropriate. Head to the movies as a group, etc. Sometimes these groups will include boys. Sometimes they won't. But they are real, immediate, and in person.
I love online chatting as much as the next person, but in person is better. Try it.