I am sorry to hear of your difficulty with depression. I have lived with depression and most of the time I have done well. So don't give up hope.
I am wondering why in 9 months you have had several therapists and have not attended school at all. That does not seem to me like a good plan to isolate.
Try not to get into who in your family has a history of depression, stay in the moment and take care of you. I would suggest CBT therapy if you would go back to a therapist that uses CBT.
I am sure there is a thread in this forum on CBT. I will try to pull it up for you.
Here is the link for CBT in the Anxiety Forum:
Maybe some one else knows where the depression forum one is. It was an excellent thread.
Take care and keep posting.