wide awake

Can't sleep I've tried everything but I'm wide awake every night till around 5 am it's doing my head in. Just knowing I have to be up at 7/8/9am kills me when I know I won't be getting sleep. I can't function properly like I'm finding uni work hard to understand and I can't ever be bothered to exercise anymore. It went back to normal for a while over Christmas and boom back at uni same old problem (it isn't that I'm homesick I love my mates here and I only live an hour away)