I'd like to welcome you here. It is a friendly and caring place, however it can sometimes be slow, and I guess you have been disappointed that you have not been answered before now. I'd stress it is nothing to do with you at all, or what you are posting about, it is the system itself.
OK, having said that I've read though your post. It's a good one, it explains how you feel very clearly. And by the sound of it life has given you a hard -and worrying -time. The things you say, feeling removed, panic attacks, crying, feeling like shit and all the rest need to be fixed.
Life can be so much clearer and enjoyable.
Can I suggest you seem to be going about things the hard way? You have not mentioned doctors or psychs or even councilors, but have gone to forums and Dr Google. It's easy to understand why, forums may have people your own age and the internet is easy to search, however getting a processional diagnosis is sensible.
Once the problem has been identified then the right actions can be taken. 2 years or so of not feeling like yourself is enough.
So can I suggest you talk this over with someone you trust and get them to take you to the doctor for a long consultation so you can explain taking your time -or even show the post you have made. Then take it from there.
If you have seen a doctor it does not sound as if the treatment is working, and you need to go back and say so.
Now this might seem rather a disappointing first reply, however I've suffered some of the things you were talking about, though I was older, and only started to improve with medical help, now I'm good.
You have quite a choice of people to talk to, a parent of course if you get on well, a school councilor, or you can contact direct, either the Kids Help Line (1800 55 1800) or Headspace (you can find the closes Headspace center at https://headspace.org.au/headspace-centres/)
The idea using any of these is to see a qualified medical person and get a diagnosis.
The chances are gong to be you will find it is something that responds well to treatment. Treatment may be very simple, and in any case is not scary, not like the scariness of wondering what is wrong.
I would like you to talk some more here, I'm afraid you do need to have patience, but we will get back to you if you post.