Could you possibly take a little time off from school while you work on getting your depression under control? I know that even the smallest task can overwhelm you when you're depressed. Criticism can be a motivating force, driving you to work harder and prove that you've got what it takes, but not when you're suffering from depression. I can't begin to imagine what it would be like to pursue an education in a hostile environment while depressed. I think the only way to get through it would be with a high degree of emotional resiliency.

Best wishes to you, whatever you decide to do next.