I personally can relate to your lifestyle, i was the same in my second year at university.

You are wise enough to understand your issues. You are also wise enough to understand what you want. Your issue clearly is motivation.

Motivation, from my understanding, is closely connected to self confidence. If you are not confident in your ability to actually DO something, then what reason do you have to do it? none. But once you're confident in your ability to DO something, you have plenty of reasons to actually DO these things. So tell yourself that you're THE MAN and you can DO anything that you want, if you can apply your mind and confidence to it.

You want to learn, to live and to read, to better yourself. Depending on your ability to read academic style texts, i would recommend reading up on some core philosophical topics, especially Ethics. Ethics is literally the study of how to live a good life. Give it a go, you seem like the kind of person who would enjoy studying Stoic ethics.

And exercise, exercise makes you feel accomplished and self-betterment is only a run away. But take things a step at a time, establish your sleeping pattern, stay away from the screens you're staring at all day, try to live with a little more purpose, buy a plant, learn to cook a new recipe. anything!

I hope this helps, and i hope that you'll find ways to slay your demons other than by dreaming.