How to explain to my friends why I'm "different" all of a sudden?

I've had a rough year, and pretty much everything that happened is my fault. Well, I'm working on patching it all up now. So in order to do this, I realized I needed to make some changes. I got rid of facebook, canceled my phone, and I'm taking some time just for myself to figure things out and kind of "start over" and make some changes. I haven't been hanging out with my friends and I always make excuses. At school, I've always been a social erfly but now I'm not sure who my friends are and I don't really talk as much and I've been focusing my attention inward. My friends are bad influences and I'm trying to break off from them. I hate all he questions I'm getting. What do I tell my "friends?"