I have mild insomnia, which means (for me) that not every night is a struggle to get to sleep, but I get insomnia about 1-2 times every week (my sister used to have insomnia pretty badly, and was prescribed Stilnox, which has recently been taken off the shelf, if I'm correct, due to bad side effects). Insomnia is SUCH a pain. You can feel extremely tired but not be able to get to sleep. I don't really know what helps... I've tried exercise (taking the dogs for a long walk at night), breathing exercises and stuff like that. I remember one night I had insomnia so bad. I planned to go to bed at 11pm and I didn't get to sleep until 6am the next day, and this was a school night! It's really funny, since I couldn't get to sleep I thought I'd use that time to exercise instead of just lying there doing nothing!
I've tried listening to calming music, but that somehow makes me stressed and doesn't make me tired at all, and I read every night but very rarely does reading make me tired. I know this sounds strange, but the time when I have the most trouble getting to sleep is when it's a full moon. I need my room to be pitch black and when a full moon is out I can make everything out in my room because of the light.
Pretty much every single night I wake up constantly. Some nights I wake up every 1/2 hour, other nights it's every 2 hours, and some nights I wake up at exactly (to the second) at 3am.
I wish I could offer some solutions, but unfortunately I'm on the same boat as you.