I found a
discussion on Drugs.com pertaining to this. I'm not sure how much help it will be to you, but feel free to peruse it.
Trying2Iso is correct about Wellbutrin being one of the main first-line treatments for coming off meth/amphetamines. I, too, am unsure about whether or not there may be an AD out there that can be prescribed specifically to someone coming off of opiates. What you seem to be describing is Post-Acute Withdrawal Syndrome (PAWS) which will, indeed, leave you with residual withdrawal effects long after that initial hellish first week is over. One can see the same pattern regarding benzodiazepine withdrawal.
Since the use of opiates stimulates changes in the behavior of such a variety of natural neurotransmitters (serotonin, dopamine, norepinephrine, endorphins, enkalphins, et al.), I am highly doubtful that one could, as with methamphetamine, narrow down the list of anti-depressants to one ultimately effective one for your situation. This situations sounds as though it may best be addressed by visiting a psychiatrist, explaining your situation, and digesting the feedback you receive from him/her. There are many psychiatrists out there who, for instance, specialize in working with patients undergoing CBT; likewise, there are psychiatrists (like my own) who specialize in treating individuals with comorbid histories of substance abuse and dependence.
Googling "substance abuse" + psychiatrist + directory + [insert state/province here] will likely yield you some interesting information, and I encourage you to try it.
How long have you been freed from the beast of burden?