Lose the word "when" from you vocabulary. You were put here on this earth for a special reason and we all need you so lets just get you a tune up to make things better.
ECT, my friend had it. However she had gotten to the place where she was non functionaly, anorexic and weighed only 88 lbs. 40 year old Mother of 2. She was in an out of treatment for the anorexia and finally the physicians had to deal with the depression to help get her feeling better and start eating again.
She had a series of OCT and when we would see her after the treatment she was very foggy, flat affect. She did get better but her underlying problem was her living relationship with her husband. Once that was taken care of she improved.
I know how the meds stop working for no reason at all, but the drug companies keep come up with new ones so I don't thnk you will run out of options to try.
Also, get outside in the sunshine.................don't stay locked in the house all winter. Be a kid again, make a snowman, go sledding, have fun.
Be sure to tell you physician how you are feeling, be honest and don't be afraid. We are all here for you.