Zaqqaz, I feel your pain. Insomnia is awful.
Are you open to any other recommendations other than a benzodiazepine?
If not, how long do you want the effects to last? Do you use benzos now or have you recently? If yes, what kind and how much?
For insomnia, I've done everything from sleep hygiene (haha) to heavy meds (everything you've done except trazadone).
Seroquel: Of all your other meds, Seroquel still 'works' for me, but I just feel half-asleep the whole next day and the sleep was not restful. I don't use it anymore.
Here's what I can think of:
-Carisoprodol (Soma)
-Benzos: Clonazepam or alprazolam (Xanax)
-Mirtazapine (Remeron)- atypical antidepressant
-Melatonin & other natural stuff
-Clonidine
-Doxepin
My opinions and experiences:
-I don't recommend Carisprodol because dependence and abuse potential are high and the withdrawal.
-Same for benzodiazepines and as truenamebrand mentioned above, they don't last long. Withdrawal ranges from not pleasant to hellish.
-Mirtazapine worked for me until it didn't.
-Melatonin has milder effects for me than Seroquel, but exactly the same 'dirty' sleep. Oh, and it plunges me into deep depression (which is a documented side effect of this "harmless" and "natural" sleep aid).
-Anything else natural (e.g., valerian, chamomile) has no effects or side effects for me.
What works for me:
-Clonidine less than or equal to 0.1 mg. I don't use it very often or in high dosages because it lowers blood pressure. Studies indicate it doesn't produce as much R.E.M. sleep.
-Doxepin (Silenor) puts me to sleep and I stay that way.
It's NOT controlled and low-dose doxepin is for patients with sleep maintenance insomnia, which is waking up frequently or early in the morning and not falling back asleep. It works for insomnia at doses in single-digit mg doses (3-6 mg). It does NOT work better if you take higher dosages.
http://www.mdedge.com/currentpsychiatry/article/64062/sleep-medicine/doxepin-insomnia
Note: I have also used Ramelteon (Rozerem) successfully, but it is indicated for late sleep onset, which isn't your problem.
Good luck!
Best, CD