Just a quick little update in case anyone is interested (it actually isn't all that interesting really!) - no drama, no issues, no nonsense, no nothing - doing great, all good.
Sleep was relatively normal within six weeks of coming off the methadone, that two week mirtazapine script after I stopped the gabapentin etc was certainly was a life saver. A total PAWS avoidance machine, can't rate it enough. A bit achy and lazy for a few more weeks, sleep a little broken occasionally, but certainly nothing to really complain about. Just over two months after my last dose of methadone I felt entirely, 100% normal.
I've just been working and studying and having fun and just getting on with life. It all seems like a bit of a fuss about nothing now, which is absurd, considering how massively huge a deal it was at the time. I just can't understand why I didn't do it sooner.
All I can say to anyone who is reading this, and considering making 2015 the year they knock the opiates on the head, is do it. Plan it properly, but don't work it up to be something so much bigger than it is - it is not insurmountable. In my head, prior to actually doing anything towards quitting, I'd made coming off opiates into a monster. It's not, it really isn't. It's doable, it's not the worst thing in the world, and you WILL sleep. A planned reduction taper (e.g. from methadone) is nothing like acute heroin withdrawal. NOTHING. I wasn't one of those odd people who could handle acute withdrawal - I really couldn't. But a properly planned taper (albeit an apparently ridiculously fast one, as some of the contributors to this thread thought!) is completely different. It's possible, it's entirely achievable. Try.
Enough evangelising - Happy new year all!