Putting 2 and 2 together to make 53, I don't know how much pain you're getting on an ongoing basis, but if it's significant it could also explain a major part of the insomnia, even if the pain doesn't seem a direct factor. The basic concept is the pain cycle activates the fight or flight response, and while the immediate response may die down quickly, the fight or flight response remains activated and sensitized in the background for hours afterwards. This is exactly what triggered my insomnia.

In my case the pattern was I'd develop significant pain while at work, I'd come home and have continuing pain for some hours, but usually by about 11PM I'd be relatively pain free. And at 4AM I'd still be staring at the ceiling and wondering why. Then I did my pain clinic's pain management course, they mentioned the ongoing background activation and {lightbulb moment!!}. I discussed it with the pain management team afterwards and they confirmed that would have been exactly what was going on. I now have sufficiently good analgesics not to have pain on a continuing basis, but the insomnia seems here to stay.

Obviously I don't know that's what's going on, but you've mentioned sufficient things that sound like my own experience to make me go 'I wonder?' Feel free to ask any questions you want (by DM or email if preferred - david.gillon @ blueyonder.co.uk)