I am really struggling, have been for a while.

I'm 16 year old boy and moved schools two months in my school year. I moved mostly because I felt like I wanted to experience something new. Also a lot of my friends left this year anyway and I had felt a bit lonely. I was at that school for a good two months before I made the switch to my new school this year. The school I am at right now is a good school academically however it has really impacted my mental health. To the point where I just have a feeling of wanting to escape life or disappear. Suddenly I feel a lot more lonely and feel completely different compared to everyone. The school is completely different to my old school also, its a grammar school fyi. I talk about my depression to my friends and parents but it seems like they dont care much and/or say stupid stuff like "get over it." It just makes me feel even more alone because I feel like no one knows what I am going through. Getting bullied also, not terribly but just teasing making fun of my dumbness. I am in year 11, so its a very important year in highschool and I feel stressed about my schoolwork on top of this and I am behind as I came late to this school and feel if I go back to my old school that will make it worse. However, I still like this grammar school because its got good oppurtunites that my old school doesn't. went to a therapist at school to talk about it and got diagonised with 'severe depression' I will see the GP tomorrow. Any feedback is greatly appreciated