First off I want to give you huge (((hugs))) You sound like you're in a very difficult situation right now. I'm so glad to hear your daughter Hannah has made it through every obstacle so far...as you said.
I've never been in this exact situation before. But I can relate to some of the feelings you expressed. I was a young mom and young bride, having had a baby at 17 and getting married at 18. I'm 26 now.
(hope I'm not repeating any one else's advice... I didn't look and see)
I don't know how your conversations with your fiance have gone when you've brought up the subject. But my advice would be to use as many "I" statements as you can. For example insteand of saying "When you bring your friends home and they are on the sofa when I wake up, you really upset me." say "When I wake up in the morning and I see someone sleeping on my sofa, I feel...." I've learned that the moment I start making it about him..and saying "you this" and "you that"... he immediatly goes on the defence. And vice versa. I don't like it when I feel like he's pointing fingers at me.
No matter what my husband does, he doesn't MAKE me feel anything. My feelings are my own and I control them. There may be an inital reaction to something in my heart, head or gut. But what I choose to do with that feeling is up to me.
Also, don't threaten. I'm not saying that you do. But you mentioned, for example, staying with your mom for a bit. Don't threaten to do this. Just let him know, (not during an argument), that if this is how things are going to continue, you are going to consider different living arrangments...even if they are just temporary.
My husband and I have seperated twice. Both times, it was I who made the decision and left...with the children. I, too, went to my mom. It wasn't easy on the kids, but neither was living in an unstable enviornment where mom and dad argued all the time.
I have to say that it changed things and now I can't complain too much about my husband. He's grown up a lot. I have as well. Our seperations really helped me see things about myself that I hadn't recognized before. Now we don't really "fight" or "argue" anymore. I attribute that to two things... 1. we're too darn tired from rasing 5 kids to argue and 2. we'd rather just discuss things, when the kids are sleeping or not around. than to get all angry and mean and yell like we used to.
I do hope that your fiance sees that his behavior is having a serious affect on you and you're not just nagging. Perhaps you two can come to a compromise, so that it's a win-win. Also, do you ever get to "go out" or have friends over? I think if you don't, doing something for just you...and noone else, should be part of the compromise. Don't be afraid of being selfish... we all need time to ourselves.
I've gone on long enough. Sorry! ((hugs again)) to you and Hannah. (beautiful name by the way...one of my favorites!)