Yack I want you to understand that you have rights. Mental health issues are very holistic in their effect on our lives. Every part of our life is affected. Stay strong and I would research on my own to the protection you have under the law and your graduate school bylaws. I am a returning student myself and I shake in my boots at your situation.
My advice is try to be strong and confident which is the best weapon in overcoming stigma and discrimination.

Best of luck and warm wishes

Danielle V.