I am often the same way. I used to avoid doing homework, now I procrastinate on things like filing tax returns or calling back friends. It's a very damaging behavior and has cost me dearly throughout my whole life.

I don't know an easy solution but talking about this to people who listen without giving advice helps a lot. I haven't tried therapy for this but I think it could help too. The most dangerous part is to have this as your embarrassing little secret you can't talk about.