Here is what I recommend:
Training: Train hard and relatively heavy (failure at 6-8 reps). Do basic, compound, heavy movements like deadlifts, benchpress, military press, squats, barbell curls, etc. Don't worry about "shaping" movements (like doing flyes for chest). Do only a few sets, but train with intensity and 'til failure.
Diet: Eat EVERYTHING. Eat lots of protein, like you have been, but eat everything else. Eat pizza, ice cream, chocolate milk, weight gainer shakes, you name it. You eat enough of this stuff, and you will gain weight.
Rest: Keep stress out of your life as much as humanly possible and try your best to get 8 hours sleep every night. Take naps whenever possible too.
Steroids: Once all of the above is in place, use steroids that promote big strength and size gains such as Testosterone, D-bol, Anadrol, Fina, etc. GH and Insulin are options too but more for the advanced user.