Okay so I am going to do my best (also for the record when I said what I said about others wanting me to walk away it was more my friends who are bias in a sense) I honestly hadn't had time to truly consider your questions so let me give this more of a shot.
Reasons for wanting to save my marriage, obviously Loving him is a part of it, Him being my Number 1 best friend is a large part of it too. We have been through alot together and he has supported me through some very difficult things and vice versa. For one I truly believe in my gut that this isn't really what he wants, I believe he is afraid of being in an unhappy marriage for years and years like his mother was, so he feels unhappy right now and being a pessimist he has issues seeing things getting better. Sorry im ranting a bit here. One reason I want to stay together is my 7 year old, no he is not his, but he has been an exceptional father figure to him, he plays with him, teaches him, wants the best for him. They have a good strong bond. We truly understand eachother, we are 2 very different people in alot of ways, we do have a lot in common as well, but our differences have caused us both to think things differently and try new things, and we have both grown so much together due to this. We both believe we are better people because of eachother. There are things ive been doing such as cheeseless tunnels and privacy boundaries things that I have done to push him away in our relationship that I have recently come to realize, he has been very patient, and reassuring and kind to me, and i believe at times i took advantage of that and I am changing these things for me, whether we stay together or not.
My H is a good person, he has problems I wont pretend he doesn't. But he has supported me, and has had a rougher family like then most and was taught toxic behaviors from his parents which I have seen him learn and grow away from tremendously over the years we have been together. It's hard to truly explain these things but we have truly helped each other to grow for the better and I believe we can still do this. I believe we can come out of this hard time and be stronger for it. And Honestly I already have forgiven him, completely, mostly for myself, but also because I understand so many dynamics of things that have caused him to be in the "grass is greener" mentality.
And as for the OW situation, I believe him because I am trusting my gut, and I can't really describe it more then that, I just know it to be true, also in DR when Michele discusses Infidelity and when the spouse wont give up OW and wants divorce, its said to pretty much forget the OW because it wont help my marriage. I have read stories of women who's husband left them for OW and they DB'D and ended up saving their marriage, I have faith because of these stories and because of the years of experience and the faith I have in my relationship. I am not saying part of me hasn't been angry at my H or that it hasn't been incredibly painful. But I don't believe infidelity has to be the death of my marriage, I believe we can get through this and have a very happy Marriage, and sometimes there aren't words to explain why that is, its simply my gut and my faith.
As of now I have already stopped sleeping in bed with him and having sex with him. Also to be noted, my husband had tried to stop us from sleeping together but because of my fear or losing him and wanting to feel close I did push my way into us still sleeping together and sex originally so he is not as manipulating as some might think. But after reading more and taking time to truly think of things I know now what i was doing was wrong and I am backing off. I told him that unless he stops talking to other women and decides to work on our marriage I will no longer be sleeping in bed with him or having sex, I saw the hurt in his eyes and he said he understands. So I am starting to set boundaries.
I am currently reading up on boundaries especially for my specific situation. I know I have to back off and not give certain things to him. In DR it also says I should be positive whenever I am around my H. One story in the book says a W became such good Friends with her husband that he had ever talked to her about the OW and eventually they got back together and their marriage has been great ever since. So this is currently my focus, is being his friend. I understand your confusion in my decision, my H wants a divorce so I really don't have much of a say in any of this right now. So like Michele says many different times, in many ways, if you want to save your marriage, you have to get over the "its not fair I have to do all the work right now" and your pride. So that is what I am doing, my H is depressed and scared and yes he's being selfish right now, but our Marriage is bigger then this moment, thats what I believe.
As for the boundaries and R talk, I don't know much. Honestly part of me just wants to know why he even wants the D as we were happy a month ago, I feel most people on here at least got some reason from their Spouse in the beginning, I don't fully know what all the issues are, and I'd like to know to work on them. But if it would be better for me to not ask about why he wants the divorce, then tell me that. I honestly don't know if i should just not know or ask right now, thus why I am writing on here to ask for advice. As I have said I have already set boundaries with the intamcy and sleeping in the same bed, we are currently sleeping in the same house and I am unsure what other boundaries need to be discussed again that is why I am asking for adice.