I have to agree with all who said you might be overmedicated. If you weren't on Zanax it might have been Ativan (lorazepam ) or another type benzo but I find it strange that any doctor would be keeping you on that or many of the others you mentioned. Benedryl to go along with the meds? Isn't Benadryl used for allergies? Maybe you should speak to your doctor about going to a sleep clinic, they could get to the root of the problem. Sounds like you might have some kind of sleep apnea and maybe you are on the wrong meds.
Just be careful and check your meds carefully, if you want to wean yourself off you might need help with that, it has to be done real slow.

I hope you'll find a solution to your problem , I know going without sleep can drive you to the edge sometimes.