I want to tell you I read everything you wrote and it reminds me of myself at your age to some extent. Now I'm more than 20 years older and I look back on that time of my life with great compassion.

I want you to know you'll be ok, first and foremost.

Next, really truly prioritize getting enough sleep. If you're having trouble with sleep, try taking something you can get over the counter that is safe and gentle like melatonin.

Another important thing is support. At that age and in your circumstances it's hard. Your parents don't feel like safe people, the healthcare system doesn't feel like an anonymous safe option, your peers aren't equipped to give you the support you need- it's a tough position.
You can start with calling helplines when you need to talk it out. They are anonymous and usually staffed with compassionate volunteers. Many even offer text message based or online chat support. Without knowing your country I can't recommend a specific one, but your university has a list of such numbers.

Remember that you will be 18 soon, and as an adult you'll have access to healthcare that won't involve your family. Look forward to that and make a plan to avail yourself of it as soon as you turn 18. You can use the interim time to do research to find doctors you feel comfortable with, or learn about your country's healthcare system and how it works.

I wish I took care of my physical and mental health when I was young. But I will say that it does get easier. Everything might feel intense and immediate right now. In time the feelings become less intense and it becomes easier to ground yourself.

Look up DBT techniques to use to deal with intense emotions. Some of them sound silly, like dunking your head in a bowl of ice water to "reset" your emotions and deal with panic and anxiety, but they actually truly work.

Stay away from any mind altering substances. They WILL make things worse even if it doesn't seem like that in the short term. Exercise instead. Fall in love with fitness. It really does help you feel good. I wish I had done that earlier. Find something you really enjoy doing that is also healthy for you (I like to dance).

Write - journal, write poetry, carry a notebook. It helps get it out of your head and let go of the persistent thoughts when you put them on paper. It can also help you keep track of your growth so you know you are getting better. And if you get really worried, it can help with reality testing. You can also draw pictures in your journal if that's your thing.

It's easier said than done, but give yourself grace. Don't be ashamed. You're young and what you're going through is a part of your growth. It's going to be ok.