Severe Depression

I seem to have trouble being medicated for my clinical depression.  I was on Prozac for ten years and it suddenly stopped working.
Nothing has helped me as much as Prozac.  I have been given many drugs.  Most of them have given me awful side effects.
I am on Zoloft now.  It gives mediocre results.
I feel suicidal most days. I will not kill myself. The pain is almost unbearable.
I am very isolated.  Very lonely.  Have agoraphobia.