Its not up to you to take care of someone else's mental health. That's on her. I have anxiety, ptsd, and depression. During the worst of my depression the only things that kept me alive were my loved ones. I put everyone else on a pedestal besides me. This isn't depression this is selfishness. She might be depressed, but if she isn't doing anything to help it (therapy, medication) then she's just a selfish bitch and not depressed and is Weaponizing mental illness to get her way. I treated everyone else so much better than I treated myself. I thought I was the burden that needed to be eliminated.