School is not set up for taking personal leave, but there are better ways. Mondays are not that bad, it is the ending of the weekend freedom that bites.
You may be lonely in your local world, but you are well liked here. That may be part of the problem, everything here seems so normal, there is a relaxation, and the world finds us with defenses down.
You mentioned losing your steely edge, the character that helped you to survive, and I too have gone a bit soft since being here.
The world comes creeping in, catches us by surprise. Action must be taken, and you voted.
Education can destroy a love of learning. Older people I have known who went back to College report that they stopped reading for enjoyment, when it was assigned as work, and it took several years out before they read for enjoyment.
There is the drive to get through mainstream school, no matter the costs, but driving too fast usually turns out bad. Your mind is chosing, it needs development time, naps and rest.
We are all prisoners here, of our own device.
You lucky one are at the point where growing up, school, is hard on many, then throw in some other issues, and you turn off onto another road.
It is all a mess, it is not all a mess. All at once is not working, other parts are fighting for survival.
Your methods are shocking but effective, but stopping some things is not the root, you need some me time, body and mind , and hay fever, watching grass grow.
You are not you, it changes so fast at your age, but each is an important step, one must be the first half of sixteen to do the second half properly. Without intergrating self, you will be lost forever.
The new goal has to be being happy being yourself, and then you can think about taking on other things.
You doing well is not measured by anyone elses clock. You have expressed that you are more important.
Drop the school work, get some sleep, for nothing works till you are happy being you. High School is not that important, and I think you could pass without any study.
Till June, one more year? Work it that you can take the finals, and think about who you are in Sept.
Is early admission to a university possible? Life does get better. University is three days a week, and even Freshmen are a better class of people.
Lots of psychological hugs to you, and caring.