Moreta, have you talked to your pdoc about your situation? Tegretol is my main med, too. I take 200 mg three times daily for Bipolar II and for facial pain. I also take Klonopin.
I'm wondering if the Tegretol just isn't working well enough. I see on the bottle that it can cause "drowsiness," but I would be surprised if it kept someone sleeping 14 hours a day. I know depression causes tiredness and the desire to sleep....
Of course, Ambien is a sleep medicine totally! That's its purpose.
Hope you'll be better soon!