This stuff happens a lot when you're still in jr high/high school. Teenagers can be the meanest people on earth. It's even harder for you to cope with this when you have depression.
I was diagnosed with depression when I was 11. As I recall jr high and high school were more nightmare than fun. Sorry your friend is being a jerk to you. Maybe it's time for a better friend?
I'm not sure how custody and such works overseas. Is it possible that you could stay with your dad for a while? If not, is there a local Al-Anon/Alateen? There is a list of meetings here http://www.al-anon.alateen.org/how-to-find-a-meeting
It's hardly a perfect solution, but you could get some support for what you are going through. Posting here can help too. at least it can give you people to talk to who understand being depressed.
Chronic pain, Depression, Fibromyalgia, Tennis Elbow (both arms), Arthritis (knees and fingers), Diabetes. Ruptured disk L-4, Severe degenerative damage L5-S1, ACDF C5-C6