Wow, that's a rough story!

I really don't know what to say to help you. I've been ill for over a year now (ME, a disease of extremely tiredness, muscle-pain etc.), I guess it's not as bad as what you have but I do understand the feeling of not knowing what to do and feeling like being needless to the rest of the world. A few months ago I also got very depressed. I've had medications for about six months and had to go to a psychologist. It was very difficult to talk about my feelings and my pain but it really helped. At this moment I'm mental a lot stonger. Of course the bad moment still come but I can handle them a little easier. And try to hang on to the few good things in my live (my family, husband, friends and of course my animals).
Remember you are never alone. There are always people who love you and who want to help you. It's not strange that you parents are fighting. They are also having a difficult time. To watch your child in pain! So it's rough for them too. And that's why you can help each other. Because you are in the same situation (except for the physical pain of course).

Of course I can't talk for you and I will never tell anyone what to do but I just wanted to share a little bit of my story and experiences.

I really hope you will get through this and can see the joys in life again.
Feel free to spread your heart out even on this forum if you feel like it. I think nobody minds you posting non-herp stuff.

All the best!

Naära

(Please forgive my bad spelling. English is not my native language)