My best friend switched taekwondo schools a while ago (they needed him at his old school; he's an instructor), so . . . I can relate. I saw him today, though, although only for the second time since he left. It . . . hasn't been the same without him teaching class. I haven't been the same.
So I understand how you feel. I've had lots of friends move. In fact, it seems that every time I have a best friend, they move away.