Sometimes my schoolwork suffers because I've needed to take "me time." I refuse to give up the small amounts of time for myself that I do get -- it's important for my sanity. I do not value my education over my health!!
If you don't have time to go to the gym with all that that implies (getting there, changing, working out, showering, getting back), why not take a 20 minute study break and go for a brisk walk if it's nice outside? Do that two or three times a day and you get some good sanity-saving outdoors/exercise time. Sure it's no match for spending an hour on the elliptical, but it's pleasant, and helps rest your mind.
As for not sleeping, that would happen to me quite often when I was so involved in a project right before bed that I couldn't turn off my brain. I don't sit up with anxiety often, more that my mind keeps trying to churn away at essay topics and study questions when I've finished for the night. This may sound ridiculous to some people, but I've been listening to this hypnosis thing at night the past few nights and have gotten the *best* sleep I've had in months. I wake up on my own after 7 hours and feel ready to go... For me, I need someone telling me to relax and shut down my mind in steps. I can't turn it off myself. It's soooo relaxing. Before I got this CD I'd get my FH to give me a backrub with a lightly scented body lotion. I found that to be very, very relaxing too, such that I could finally sleep at the end of it all.
Maybe try going to the gym first thing instead of studying first thing. Exercise helps me with mental alertness -- hence the little walks I suggested -- and then you don't have to worry about being too exhausted at the end of the day for exercise.
I'm sure you know this, but be careful with sleeping aids... Make sure you're using the proper dose and only for the recommended amount of time, lest your body start depending on them for sleep!
Good luck and just remember, the year's almost finished and soon it'll be summer again!!
