Here's my two cents. Try to stay on top of your work. Chances are you will get some time before an assignment is due to stay on top. Thats the biggest thing.
Next, while going out and having fun is important, going out all the time and stuff isn't the best idea. Decide on like maybe once a week or whatever works for you. Takes a little bit of discipline, especially if your friends go out loads, but I think it will be worth it.
Next, try non caffeine alternatives. A cold shower jolts me to my senses in the morning, so try that.
This website offers some idea.
Lastly, have you told your uni about your health problems? They often have provisions for this, such as extensions etc. Take a look
Hope this helps