I agree with all the above, and I'll add... "It will pass."
Anything so new, and so big, is weird at first. Once you get some time doing it you'll quickly think "How did I live that other way before?" Just give it time, use the tips above, and above all... look for the good things you can do alone! Stay up whenever, sit around in your undies, leave stuff out if you damn well feel like it! You can let the dishes pile, and wash them when you feel like it! You can watch whatever you want, eat what you want, there are many positive things about living alone. Think about some of them, do some of them, it will help. Good luck.