Choc, been exactly where you are. Everything you wrote I could have written. I'm on Amitriptyline too, for the same reasons. I also take Melatonin which I order online from the States.
I only take Ami twice a week because I found that the more I took, the least it work. It also came with some side effects, weight gain and worse, my bowels didn't like it at all. I also have to be careful because of a family history of glaucoma. I now take 10md twice a week. It's enough for me because even though I don't sleep well most nights without it (and indeed, even occasionally on it), at least I know that in all likelihood, I'll will get a better sleep in a couple of days and after 4 years of disturb sleep, I know that somehow, miraculously, even though it doesn't feel like it, I will somehow cope the following day, even if badly.
Saying that, my GP has assured me that it was safe to take, and could do so every night if I wanted to. It is not addictive and a dose of 5 or 10 mg is little (compared to 50mg + if taken for depression).
My anxiety is a lot better since I've been in it, but it was already much better before I started, so don't know if it is because I'm now full menopausal or whether it helps with that too.
I was on HRT for some time, tried different ones, different doses, but it never make any difference with my sleep. It doesn't work for all. Working ft in a demanding job certainly doesn't help, but some people have no option but to keep going, so I really know where you're coming from.