Hi Mikes:
Research Post Acute Withdrawal Syndrome (PAWS). When I did, it was one of those aha, now I see what is going on moments. It helps me when I understand that it is part of the healing process, and, alas, can linger for 6 months to 1.5 years.
My struggle is great also. I posted here a while back after about two weeks off of a nasty vicodin habit, feeling that "pink cloud feeling," then relapsing three times. I am currently clean and sober, but the lingering depression and fatigue is a grim reminder that I have a long way to go.
We share a similar past. My brother died of alcoholism at 25 and my grandmother died from benzo abuse at 72 (she was lucky).
I don't know much about the drug you are asking about, but I think that your questions have already been answered.
Stay strong,
MK (another mike)