Ok, that's key information, imho.
Here's an experiment to illustrate how simple the equation has become. Hold your breath. As your air begins to run out a minute or so from now, what will be on the table? Everything. Anything that has to be done to get that next breath. Anything at all, right now.
That's your current situation. In this potentially lethal situation, the only rational action is to do whatever is necessary to address and overcome the threat right now. Nothing else matters.
Some part of your depression probably isn't arising from external situations. All of us deal with depression on some level at some time, it's just the human condition. Winning the lottery and moving to a beach house in Hawaii won't fix that part. This part of human existence is sort of a life long maintenance job which must be accepted as the price tag for being alive, just like eating and sleeping is a non-negotiable price tag.
That said, some external circumstances are more conducive to mental health than others, and these are things we can grasp with both hands and change.
If you're being overwhelmed by having bit off more than you can chew, it's time to start tossing things overboard so your ship does not run aground. If you need to take a break from school, take a break. If you need to get a job to sort out the finances, get a job. If you need to be somewhere else, around people more like you, go there now.
Our bodies and minds are not two different things, but one. Thus, we can go a long way in improving our mental situation simply by getting serious about feeling better physically. Take every reasonable action you can to make your body feel better. Do it like your life depends on it, because it might.
I'm probably three times older than you. From that larger perspective please allow me to share that it can be easy to get wound up in the bubble of a particular situation and lose track emotionally of all the other things we could be doing. It's happened to me a number of times.
When we're in the middle of some situation we can feel that if this doesn't work out we're screwed. But that's pretty much never true. There's always another way, another situation, a different road which can be taken.
As example, I struggled emotionally for years with some business failures. I had my mind stuck on a particular thing, couldn't make it work, and couldn't let it go. And then one day I'm shopping in Home Depot and it dawns on me, the worst that's gonna happen is I wind up working there, not such a bad outcome at all. I was stuck in a bubble, that's all.
Here's your homework.
Hold your breath once every day. Feel the will to live, and find the urgency to take the next breath. Whatever needs fixing, get on with fixing it.
Good luck!