Desperate to sleep - any help?

My biggest problem with bipolar is lack of sleep, problems getting to sleep, waking too early etc. My brain is very easily stimulated and I find I have racing thoughts at night and cant sleep without knocking myself out with various drugs - mainly Seroquel. I also have systemic Candida which I'm seriously tryin to address but its very difficult when I have constant mood swings, and am severely exhausted from insomnia. Valerian, hops none of those work for me, they're too mild, am trying GABA and Taurine, but no success there yet. Can anyone help - continual tiredness has left me feeling very unmotivated and at time hopeless and suicdal. Like others I hate taking meds, but lack of sleep on a long term basis will make you try anything.

Thanks for help