Consult a Psychiatrist!
Clonazepam has a much longer half life and works well for sleep. Im betting that is what they would use. Trazadone would not be a bad choice either. However, titrating down very slowly could help.
As for continuous mood swings... Maybe Lithium or a different antidepressant? It is hard to say.
@Rouzbeh - I am not a doctor, but thought I could give you some feedback.
First, making adjustments to medications like this should always and only be done in consultation with YOUR doctor. You are taking a very high dose of the Ambien, and you may be on a path where the dependency gets worse if you do not establish a plan for titration with your doctor. If your doctor approves it, you might consider titration alongside supplementation with melatonin--I've had some success there.
Your situation, in which you are taking other psychiatric medications, makes this consultation all the more important. I understand that this is time consuming and frustrating, but--the sooner you address this the better for your health.
Unfortunately, I cannot give you any advice on managing insomnia beyond what you probably already know about distractions, bright lights, caffeine, and all of the token things that have never worked for me. I can only speak to the importance of never making medication changes to benzodiazepines or Z-drugs without speaking with your doctor, especially when you are taking such a high dose.
Best of health to you going forward.