Take it from someone who now suffers from carpel tunnel... 7-12 hours a day??? You should really limit how much time you spend playing. It might take years but all that heavy playing will get ya at some point. And let me tell you, there is nothing sadder than a person who loves guitar to not be able to play anymore. I weeped when I found out I had it, nearly went in for surgery and decided that I was going to play til my hand fell off rather than go under the knife... Thankfully it eased up after several months in a brace with no playing but if I play now more than 2 hours a day I am swelled up and numb for a week. I think a better idea would be less time but more effective practicing. A good warm-up to get limber and focused and then work on something that challenges you a bit. Then when you go back to stuff you were playing it has the influence of what challenged you and you play it with more ease and flare.

Take care of those hands... you'll have them for a lifetime.