eating lots of protein and carbs is absulothly the key to gain.. i even suggest to set your alarm clock and have a high protein meal in the middle of the nite.
my ex use to do that, and have seen good results..the only thing he use to wake me up as well, and found it hard to go back to bed !! :-(
just make sure you r quiet, or prepare your meal in advance...

i wish my problem was the same as you: hard to gain..