Well in that case I agree with your nurse... You're choosing caffeine drinks? What about sticking to water? Thats the best for you by far anyway. The stuff that caffeinated drinks has in them could really be affecting you a lot more than you know.

Have you tried getting out of bed at 8am regardless of what time you go to sleep? If you only get 3 or 4 hours sleep that night you might fall asleep earlier the following night. Once you get into a good routine it is easy to keep. Might be hard for the first few weeks but it will be worth it.

I really cannot stress enough how much a good sleep pattern will help your moods and functionality.