footballfan,
BP is very complicated, but your question isn't dumb. The situation that you are both in can be found in marriages without a BP spouse. Maybe if I relate how my BP affects me and my life, you might be able to see how the BP has affected your wife, and your marriage.
Keep in mind, it also really depends on what type of bipolar your wife is dealing with...BP I, II or mixed states. That's really important.
I am BP II, also experience mixed states... and during my times that I am depressed, my insecurity can really get the best of me. I have a boyfriend who lives with me. We've been together a year and a half, living together just over a year now. I know when I am experiencing my lows (depressive symptoms) I feel worse about myself, I worry that he'll leave me or I'm not good enough, or he likes someone else. I'm not saying this is how your wife was feeling. When I'm hypomanic, I feel great about things, and I know that my relationship with my boyfriend is wonderful and I feel great about myself, appearance and all. My bf works long day shifts, and right now I am home all day b/c I'm waiting to back to school. So symptoms can really affect me when I'm alone. When depressed, being alone is scary for me sometimes. I get extremely lonely. If I'm alone and hypomanic, and if I had money, I would go shopping.
I have read a lot about manic states in bipolar (again, not sure if your wife is experiencing full mania, or hypomania...hypomania is "less mania") and from reading I know it is extremely common for people to do things they would not normally do... from breaking the law (very common) to maybe having an affair, things like that. It doesn't excuse this behaviour for anyone, and I know your wife would agree, but really it is what can be behind it all, the control of the illness. The symptoms are overwhelming footballfan, and very hard to manage or control.
I think that is why your wife has felt like someone else. I feel that way when I'm experiencing major symptoms. There have been things that I have felt, that I wish I didn't feel (like the insecurity) b/c my bf is very trustworthy, but my symptoms don't allow me to see that all the time. I feel like I'm not the real me sometimes. But I have learned to acknowledge those moments as the illness acting...and try to use the things I have learned, to work through them and not let them take over. That takes a lot of time and learning and practice.
What you said about "not facing problems...etc...". In the past, anything that was stressful for me, I wouldn't want to deal with it, b/c symptoms become much worse w/stress and therefore I would just not deal with the issue...It would always get worse, but I wouldn't deal with it the right way b/c it was too overwhelming for me, so it was better (not really) for me just not to face it. It was too scary to face. And it all is very scary to "talk about" as well. And hard to talk about. I still don't really like talking to my bf about my symptoms, the illness. I would much rather talk to someone who is BP and understands, or my pdoc. So it really is something that is hard to talk about. And guilt plays a huge role as well. If my bf and I have a fight and I know that my symptoms may have played the bigger role, I feel ashamed, that I wasn't myself, I feel guilty for upsetting him or us.
Sometimes, I push my bf away when I'm not feeling well. He'll ask me what's wrong, but b/c he can't understand fully, I push him away and tell him I'm fine. I'll become distant sometimes.
I'm really hesitant to comment on the specifics of your marriage, b/c I don't know you or your wife, AND...I'm not a professional. I do think she is remorseful, sincerely and I also know this is a struggle for you.
I hope this helped a little, keep in touch.