Salaam aleikum, sister.
I suffer from mental illness (generalized anxiety, manic depression, PTSD, psychosis, and by one diagnosis, bipolar disorder). My illness is such that I was just granted disability by the US government, and soon I will be removed from the work force. I have many bad days where it is hard for me to remember to pray, wake up for prayers (even prayers like Dohr and Asr, as I have to take a lot of naps), keep my concentration during prayer, or keep from being dizzy so that I can stand and complete the prayer. Because of my illness and my medications I make up a lot of prayers, and combine prayers where it is allowable. Even when I cannot get out of bed, and/or am having a spell where I cannot remember the prayer, I will bring up the prayer on Youtube and pray along with it, even if I have to lie in bed and not go through the physical motions, as happens on occasion.
Fasting, however, is a different story. Follow what your doctor says. You are required to make up the fast if your condition improves, even if you make it up one day at a time with days of non-fasting in between to maintain your health, but you are not required to make up the fast if your condition does not improve to a point where a doctor says you can fast again.
May Allah grant you respite from your illness, and strength during this test.