After reading some good advice from you on my thread, I read yours and noticed you found your wife was bipolar.
I met a friend who developed bipolar disorder when I was in university through a youth program - he was 17 at the time. Later, I moved and as did he, both of us eventually coming back to the same city. Having gone through a few cycles with him, I noticed a few things that I thought might be helpful to you as you live with your W:
1. When manic, they are going to do things that they will later regret. It can send them into 'personality shock' as all the behaviour limits in thought and action are lifted and they do and think things that can't be just erased. Mutual forgiveness and 'repentance' are needed (in other words, bad choices when manic don't make bad ones when normal OK).
2. Meds are a must if others around want a normal life - maybe a lower dose. By the time your W is manic/depressed, it might be too late to convince them to voluntarily take the meds, but it also takes longer to come back to normal. Almost every time he was manic, he was off meds.
3. Don't leave things hidden. He didn't want to talk about his condition with his W and they had a lot of problems because of it. His W and her family didn't know enough to understand how to get him talking. You mentioned that your W wasn't spilling everything to her psych., which only leaves more for her during a depression cycle.
I really hope your W's condition is better than my friend's was. You want to know more about her affair and personally, I think this is your right. I also think that the more that she doesn't disclose might leave her with more baggage than she can always handle - and you.
When I was reading some of your posts, I began feeling that you felt that some of your M problems had to do with your choices earlier in your M. Then, I reimagined the situation with the Bipolar D. which may have been present but undiagnosed, and then I thought that depressive and manic episodes exaggerate emotions, which could lead to the EA and PA.
Going through this with your MC is good, but maybe having her answer just one question at a time is enough.
If I've misread/misunderstood - sorry! If not, I hope this post helps...
