First thing; practicing is only useful if you practice effectively. That means working towards something. Not just scales and chord progressions, but the scope and purpose a genre of music.

The other thing to deal with is your approach to music. I borrow a page from the jazzer's book on this: Learn everything you can about how music works (the theoretical stuff), and 'forget' about it when its time to play. You don't actually forget the theory, but its not what you focus on. Theory is not a road map. Sorry Jeff, gotta disagree there. Its much more like a vocabulary, and the rules of grammar. It won't lay out your destination for you, but it will help you to say what you need to say.

Which brings me to the final thing. Musicians don't play just because we want to. We play because we have to. Like the visual artists that sketch on scraps of paper, we have stuff inside that has to be expressed. Find some music that gives a voice to what you're feeling, and then play the hell out of it.

Which brings us back to the first thing...