I think you have to push yourself in the weight room more... you should be training just about to failure on each set, so if you are lifting for 10 reps you better find a weight that you can barely do 10 times!
Yeah, I think you mainly have to work harder in the gym.
I would structure your meal plan better as well, try to keep the carbs around the workout and breakfast, and eat some more big time muscle gainers like steak, pasta, chicken, etc.
It looked like you were mainly eating junky deli sandwiches... that won't put on the mass like a good ol steak will from my experience...
.......or chicken pasta, steak and potato, chicken and steak pasta, big ass post workout shakes... etc.
try my post workout shake, it kicks ass
1.5-2 servings whey
3 cups skim milk
1-2 tablespoons dextrose
1 large banana
Blend all that goodness up and enjoy
Oh... and I would definitely consider training more than 3 days per week. If you really care about gaining muscle I would do 5.