While protein is used for repair, eating more protein won't automatically lead to bigger muscles. It's the work you put in and the rest you give your body that helps build muscle. Though it may sound illogical, try decreasing the amount of days you weight train (do each body part twice a week) and go as heavy as you can when you do workout. The day after your workouts, give yourself permission to sleep and extra hour (or take a long nap in the afternoon). When bodybuilders work on building up their muscles, they sometimes go to extremes of doing nothing but working out and resting, and avoiding much cardio at all.
