Is my best friend's boyfriend controlling or what?

Well, toward the end of the email it sounds like she's opening up a little bit more. One thing you should think about his kicking his A-S-S. If he is being this controlling about her friends, imagine if he does worse things to her in private. As for being your friend again, talk to her one on one even if it makes him mad. Ask her what's going on. Remember! Don't criticize her! Tell her that YOU miss her and that YOU feel lonelier without her.Ask her if she'd like to hang out. If he happens to see you talkign to her, tell him that if he doesn't like it, he can jump off a bridge. If push comes to shove, it might be time to realize that she has chosen him over you, as much as that sucks. My friend did that to me back in high school. Basically, tell her you love her, but if she can't help herself, how are you supposed to? Good luck to ya, girlie. I sincerly hope that you guys can a good friends again.