Argh! I feel your frustration. I was on Ambien for about a week and slept great, then it stopped working. I was on Wellbutrin at the same time, which gave me even worse insomnia, so I was a total wreck. I refuse to use anything that's going to leave me hungover the next day or make me gain weight. Doc suggested antipsychotics. No way. I'd rather sleep poorly and rely on coffee the next day.
I still don't sleep straight through the night, but I find comfy, soft bedding, pillows, and mattress pads help. I always sleep better when I'm kind of nestled in (but I can't stand having arms and legs tossed over me by another person). I found a clock at a thrift shop for $1 with all kinds of nature sounds that helps too. It has a sleep timer, so you don't wake up to waterfalls or chirping birds in the middle of the night. I stole an idea from the my daughter and have some stuffed animals too. (I even bought a pretty big floppy lion to use like a body pillow, but my 12-y/o son used it one night and now he's unofficially adopted it. I can't blame him. It's so squishy and soft. LOL).
I've tried Benadryl, but the active ingredient in Unisom works better for me. Pdoc said not to use them because he says they cause rebound sleepiness.
I've been using Valerian root lately. Pdoc says he doesn't know how it works, so he's leery of me taking it. He said DON'T take melatonin because it makes depression worse, especially SAD (which I don't have, thankfully. I just hate the cold of winter).
Good luck in the sleep quest.