The diet section is excellent. The base line here is that you have to eat to put on weight. You may have to wind up eating none stop. One of my buddies is about your size and stature and has a metabolism like a blast furnace. He has had to train himself to eat non stop through out the day. Even with gear he knows that in order to put on and keep weight on he must do this. Its the only way. He often consumes well over 300 grams of protien, 6-700grams of carbs and 60-100grams of fats and remains lean all the time. I can only recommend you do the same. Just pour it on with the food, to the point where you think you can't eat anymore and train till your exhausted with the iron. In my friends case he can't do hardly any cardio. You may have to do the same.