I've been down on myself for what seems like quite awhile now for various reasons. I would go more into that, but this isn't about my problems and I don't want to make this about my problems. But the way I see things that make me feel better about my problems is that I've always been more optimistic about my life than I have been pessimistic. Which is funny, because I quite often find myself cowering away thanks to that pessimism. But in my mind, I know that eventually I'll somehow make my life turn around and get better. I want it, and I need it.
And that want and need drives me to never stop.
While I am not in the same boat as you, I do find that the way I feel about my life can, in a way, apply to you. I'm not telling you to wake up in the morning and put on a fake smile or to magically wake up happy and ready to go. I am, however, telling you that you're a lot better off just doing all those things you don't think you want to do. Because trust me, you do want to. Even if you have to go to school, go out with friends or whatever, do it. Don't worry about how tired you look or are. Don't worry about how unhappy you feel you are. Well, I mean you should worry about not being happy, but I mean don't let it stop you from being happy again. The more you continue to let this loop, the worse your odds are of getting out of it. Be optimistic about where things are going.
If someone sees you and realizes something is wrong, you have to let it out and either ask for advice from them or for them to help you. It doesn't matter if it's 10 people or 1. It doesn't matter if it's a friend or a family member. It's hard sometimes to ask that from someone, but would you rather deal feeling like shit all the time, with all of this on your shoulders, or would you rather relieve yourself of all of that? The only way to do it... is to do it.
I hope you get better. I'm sorry that these words and that hope is all I can do, but maybe it can help you find it in yourself to not let your life become what it's becoming already.