Okay, so how do I make it less awkward between us?

My best friend is a guy. I've changed a lot this year, for the worse, and I have a lot of regrets about things and I'm trying to fix that. Well, the last time we talked was a month ago and he said that he misses the old me and he looked really upset and, well..he's right. I miss the old me too, and I"m working on it. After that it's been really awkward and we don't text, hang out, or talk at all, and when we see each other we act like the other person doesn't exist. I don't know; we're both acting weird. I want to apologize but I didn't do anything to him so what could I apologize for? So anyways, tomorrow we start new cles and I have a cl with him now and I know this is kind of stupid but I"m scared. I lost a really good friend, and most of my other friends are backstabbers and aren't really my friends so I'm friendless @ the moment.