I was just talking about this the other day.... I've had to leave college twice due to mental health issues . I'm very interested psychology and would like to continue my education towards that but like you I'm scared that I'll have a breakdown or something and fail. It's really inspiring to me that you have goals towards your PHD , that's awesome. I think people with mental illnesses have to push themselves pretty hard sometimes ( IMO) . If you are ever financially capable and feel you are in a good place mentally , I think you should go for it.

Better to have tried and , failed then failed to try .