If you're taking Ambien, I take it you don't/haven't ever slept well at night? Not getting enough/good sleep during the night will definitely mess up your daytime, that and having a boring-sounding job; doesn't sound like you are very interested in it so there's nothing there to keep you awake?

I'd go with having a sleep study done; you could have sleep apnea or something that needs addressing so you can sleep when it is time to sleep and be awake when you want to be awake.