i dont give very popular advice on nutrition. but i would say not to worry about food except to eat a lot more. especially fat. try and at least triple what you are eating now with fat.
as for a program, get on a proven program to add on size. dont try and make up your own till you the years of experience to make a balanced program with progression built in.
you could try: 5/3/1 with big but boring, stronglifts, bill star 5x5, or something else along those lines. im sure others will come around with more details.