Really glad to hear it. Our neural pathways get all screwed up when we are drinking and using. Our brains and body wait patiently for the external substances that we have been so faithfully delivering to calm them down. I think that lapse between when we stop using chemicals and when our brains tentatively realize they might need to restore to factory setting can be difficult to endure. It is part of the reason a lot of us throw in the towel and relapse. And it might not be a straight line equation at first, but it gradually gets better.
I spent years on drugs, did sleep clinics, etc, sleep was something I was always chasing. I cannot tell you how weird it is to go to bed at 11 and wake up at 6, I still feel like a kid with a new toy. NEVER, since I was in my late 20's, have I slept like this.
Ambien has a very short half life of approx 4 hours, hence the 2am awakenings. Because it is a hypnotic it will put you to sleep but not keep you asleep. If you can, letting your brain slowly reestablish its natural rhythm is preferable.
Keeping good sleep hygiene is really important. Get outside to natural sunlight as soon as possible after waking, it helps to reestablish your circadian rhythms. The first time I flew after I got clean and sober it was lovely to not walk through the airport with a thousand pills rattling in my bag.
Congrats!