Trying to quit opiate but withdrawal intensified my depression. What can I do? I can't seem to quit. I was depress to begin with, now it's unbearable.

Self medication. It appears that in addition to your substance dependence, that can cause depression in presence of a protracted withdrawal, your symptoms of severe depression could be related to a dual diagnosis (dependence and self medication of some other disorder, such as depression). I would suggest to ask your doctor for a referral to a mental health practitioner for an evaluation and reduce relapse risk.