I thought it was high time to give an update, because the previous journal entry was written under such dire conditions. I got a couple of meds to try to help me sleep. The first one made the akathisia (a constant agonizing need to move) worse but the second one seems to have calmed things down. Either that or that particular withdrawal symptom died down, but I wouldn't bet on that. So right now I'm sleeping largely thanks to an old antihistamin with a heavy sedative effect.
Since I didn't have to reinstate diazepam, the withdrawal continues. I'm now getting physical therapy for my piriformis and pelvic floor both, so hopefully the situation there is going to improve in the near future. I can't say that life is good, but at least it isn't living hell, and I get to sleep at night, even if I do wake up every two hours. I don't think I've ever been so glad to feel tired and sleepy.
It's soon going to be three months since I stopped taking diazepam, so I have to be getting close to a limit after which new withdrawal symptoms can no longer pop up. I've read that people have been able to return to work 4-6 months after cessation, so I assume that after I've held out that far, things will start to get easier.