If you want to gain size then you have to get enough rest. Sleep allows for maximal recovery and growth. While sleeping your body shuts down and that allows other metabolic processes to take over and work more effectively. When you are continually smashing your body with weight workouts, sleep becomes essential.
If you are having trouble sleeping, it is possible that the intensity of your training is interfering with the production of Melatonin in yor body. You can always supplement with Melatonin from a bottle. Using Melatonin is especially helpful if you experience jet lag from travelling a lot. It is quite an effective supplement.
Aim for 8 hours of sleep every night. That seems to be optimal for most people. You should feel energized and refreshed upon waking. Get out of bed when you wake up. Don't attempt to squeeze in 5 or 10 more minutes as that will likely just make you even more tired.
Sleep is something I personally need to work at. I generally get 6 hours a night and I feel refreshed enough, but there are days where I need a nap. I don't resist that and try to fit the nap in. I always set an alarm when I take a nap so as not to sleep too much. I pay careful attention to the energy levels in my body because they tell me if I am getting enough sleep or not.
Sleep is a misunderstood tool for growing bigger muscles. Don't neglect the usefulness of getting enough sleep. You will notice that you are stronger and your muscles start to grow when you get more sleep each night. We all have issues at times with sleeping, but take the necessary measures to get enough sleep the majority of the time and you will reap the rewards in the long run.