This has red flags all over it. You should not be marrying someone who is a compulsive liar with a temper until he is much better and you know he isn't lying or getting very angry anymore.

I'm not saying you should leave him yet. That's up to you. But this isn't a good situation for you. I'm glad he's getting help, that's a good start. But please, for your sake, put off the wedding until he is more emotionally stable.