So I finally went to see a doctor and have been diagnosed, which is a huge relief for me.
I have social anxiety, mild depression and self esteem issues. I haven't got any help yet because the adolescent unit would be no help to me and I'm not yet 18 so can't have antidepressants, but at least I know now. And the school has offered to put me on a part time timetable so I don't get to stressed, which is nice. And now my parents understand, so today has been a really good day for me. (Although I have been banned from coffee.)