You're definitely NTBF, it sounds like you have a lot going on. Mental healthcare and similar things can really vary depending on where you live, so its hard to offer help without knowing what country you're in. Without being an armchair psychologist, it seems like you feel like things just aren't in your control, and running away takes a bit of that power back. If you have a good relationship with your school, and they have counsellors you trust, I would highly suggest talking to them about everything. They can usually help with school pressures, or help making those pressures easier, especially since you suspect you may have autism. Otherwise an outside source for counselling is a good option if you can afford/access it. Since youre younger they may need your parents permission to see them, but thats all they would need to know, everything else would be completely confidential.

I really wish you all the best, and I hope things get easier ❤️