First things first: not a doctor. I did science but not medicine, so I don't know how this would interact with your other medications, or if it would work for you or whatever else. So definitely check with your doctor if you want to try this and definitely don't take my anecdotal evidence as proof.

However, having chronic (but intermittent) insomnia I know to some extent what you're going through (though mine seems much more manageable than yours; I'm not currently prescribed any medication for it although I'm looking to get a long term prescription for this I'm about to suggest). I had tried legal drugs (alcohol, tobacco), illegal drugs (weed, ketamine etc), prescription drugs (valium, xanax, zopiclone and others), and all either didn't work or had severely diminishing returns. What ended up working for me is an OTC drug called diphenhydramine; marketed in the UK as Nytol and the US as Benadryl (or you can ask the pharmacist for diphenhydramine; but mine gave me a dodgy look as if to say "how do you know that word" until I told him I am a biochem grad). It is an antihistamine with soporific qualities and strangely it is the only thing that works long term for me; and further I wake up from sleep after taking 50mg pill of diphenhydramine feeling very refreshed from my sleep, something which doesn't occur with anything else I've tried or (obviously) when I take nothing. Additionally it seems to have a drowsing effect for a long time whereas something like zopiclone only has a short "window of opportunity", which is helpful.

Again I have to stress I'm NOT a doctor, this is anecdotal evidence and I don't know how it may or may not interact with your other medications (I'm sure your smart enough to know that you shouldn't just take my word for it though); but I thought I'd share what has been the only thing to work for myself before the real docs come in :)