I have the same problem. It's more of an addiction than anything... like, I don't have the willpower to stop the music sometimes (not always though hehe... just when I'm bored). It made it a pain in the ass to pay attention in class.

Anyway, my advice is simple. Let the music play. You have the biggest playlist in the world. Pick something soothing (and EASY to play in your head, so no solos or whatever silly), and let it play in the background, while you do whatever exercise you would normally do. It might help you relax, and it sure is more interesting than just focusing on your breathing. If you play guitar, it helps to pick something you really know, so it's more natural.