From reading your post, I'm a little unclear of your motivation to stay with him, if I'm being honest. I worry sometimes that people stay with others in relationships that aren't healthy for them, because they want to 'save' that person, don't want to fail them/let them down, or don't want to feel like they just gave up. Or even that they are honoring the love they have/had for this person when he or she wasn't/isn't in the worst part of their illness (or whatever struggle they're facing).

I often wish my bipolar had been more evident or understood, both by me and my husband, before we got married. I wish he had been able to make that decision with his eyes wide open to how this would be with me. And I would never have held it against him if he decided that dealing with this wasn't the best scenario for him emotionally, or for any future family he wanted. I worry sometimes that his love for me has led him into a marriage that is often unrewarding, sometimes infuriating, and other times makes him feel like he has to walk on eggshells.

And if I ever got violent with my episodes, I would hope he would leave and would take our kids with him. No one should have to be exposed to that. Even when I'm in a rage, I can (mostly) control myself physically (it gets really hard, sometimes). When I can't control that (which is rare), I turn it on myself. I'm petrified that some day my impulses and emotions from this rollercoaster will make me even worse to be around, or even more volatile...sounds like your fiance is already there. At this point, I'm wondering what positive things you're getting from the relationship? Your relationship should be something to build a solid, positive future on. Do you think your fiance is able to do that at this point? You can't make him, if he's not, and you don't deserve to sit around waiting for the relationship you should have with him. Especially without knowing if that will ever happen.

I think sometimes people are also caught up in the idea that leaving the other person is something like a punishment for their behavior, and they get upset at this idea that it's due to something outside of the other person's control, more or less. A long time ago, I was seriously dating an alcoholic. It took me years to leave him, because I loved him before it got bad, and then saw how hard he tried to get better in the middle. At the end, though, the alcoholism won. It wasn't his 'fault,' but it wasn't healthy for me regardless. I had to choose to leave a relationship that was detrimental to me, because of the circumstances we were in, not the person that I knew he was when he wasn't drinking or the person that I thought he could be one day. I feel like I'm maybe rambling a bit now, but I just don't want you to think you should short-change yourself now because it's not fair to him, somehow, or you have an ideal of how you should stick it out in this relationship. You really don't have to do that, and it doesn't have to be anyone's fault. If the relationship isn't working for you, and you don't see it working in the future, this is the time to realize it, before the vows are spoken. Only you can answer if you think that there is potential for him to realize he needs help and actually get it.