How to break my patterns?

Hi everyone,
I have a problem with my everyday life right now.
I'm 18 and I've been living in a small flat for 7 month now. I'm in my last year in high school. I've been feeling worse and worse since October. I don't feel unhappy, because it would mean I have been happy, which is not the case. I don't fell sad or anything, just completely empty, stuck in a dark and cold cave.

I'm fighting to keep up, but it's getting harder day after day. I don't have any energy to take care of the housework, so my flat is getting pretty dirty, and it doesn't help. I haven't shown up at school for more than a week now. I sleep less and less, although I try to get some, but I just can't fall asleep, so I spend most of my nights trying to sleep and most of the days sleeping or doing nothing.

I have important stuff to prepare for the incoming year, but I just don't have any energy to do anything. I spend all my days on my computer. I try to do something else with my time, but I just don't enjoy anything else than sitting in front of my screen.

I would like to fix all of that, but like I said, I just unable to do literally anything else than sitting motionless. I don't have anyone to ask for help around me, so I'm looking for a way to get out of my everyday life patterns.

I tried to find outside activities, but I don't have any money to spend for anything else than the absolute necessity. All I could do outside my flat would be walking around in my tiny town. I could try to travel, but that would mean giving up school.

Have anyone felt like that? How did you managed to get out of there?
Thanks by advance.

Seems like the first obvious step would be to cut down on your computer usage massively since being on all day will drain an incredible amount of energy and make it hard to sleep.

Secondly, I'd suggest going for runs. The physiological benefits will help with everything.

With the housework-you could set yourself the goal of doing just 15 minutes a day. I have found that if you give a really messy room a really good tidy up (15 minutes a day should get it done in a few days) and then don't let it get too messy again, you only need to dust, tidy and vacuum it once a week to keep it ticking over.
Re Travel-you say you are in the last year of high school. You could plan to travel after finishing your final school year and that way you would have it to look forward to and wouldn't have to drop out of school so close to the end.
As paraiyar suggests above, maybe going for a run each day would help as well. It would help you to sleep at night a bit better and would benefit your health as well.

Running or any physical exercise could help pull you out of your rut, so yeah, I agree with doing something of that nature. But, all in all, whether you want to do it or not, you NEED to do some of it. Force yourself to do it. Yeah, you want to sit there and do nothing, but so what..do something anyway. Get out of the house, go do something. Write yourself little notes before you go to sleep about what needs done when you wake up. Get up, take a shower, and do one of those things. Start small, but you have to start.

Also, you need to remember that you're only 18 so there is still plenty of opportunity to get what you want out of your youth. You can't afford to rest on your laurels with this at all or it will pass by quicker than you can imagine.