Dear Aeofe,
Well done on reaching out and sharing your concerns. I don't know too much about insomnia, to be honest, but have certainly experienced anxiety .... for most of my life in fact. And I don't agree that it's "all in your mind". I say that because for me, anxiety is also in my racing heart rate, my sweaty palms, my short shallow breathing ..... see, it's in my body as well.
Luckily for me though I've always been a great sleeper ..... almost feel guilty about that because I know that for some people sleep is quite troublesome. I must admit though, I've almost felt the opposite is true for me, in that I have trouble waking up and can sleep a LOT sometimes. Mind you, I am also an asthmatic and so my general lung function is less than that of a 'normal breathing' person. Less air getting in means less energy.
Anyway, enough about me. It seems that you may be looking for some other solution than sleeping tablets, so maybe you could see a naturopath and look at taking some sort of herbal supplement? Or even try joining a yoga/meditation group? Please don't think that I am any kind of professional or anything though, nor that I am minimizing your issues. Just trying to think outside the square, I suppose. I know that yoga did wonders for me when I was quite young and going through a very tough time. I guess it's just a matter of doing some research to find what works for you.
Anyway, I hope that helps at least a little. My 'prescription' to you: take 10 slow deep breaths, counting to 5 for the in breath, and again to 5 for the out breath. And repeat. S l o w l y ....... :)
Take care. Hope you feel better soon. xo