Remember, men don't typically know that their wives were having affairs or maybe don't believe that their wives could ever do something like that (ie. we had such a loving & happy marriage).
Alot of women will wait to see if their affair will turn into a permanent relationship or wait while they are looking for a new relationship before ever considering an actual real divorce. Some women will play around for a while, because their affairs wouldn’t be as exciting if they weren’t married, and they don't want to let go of their security blanket (marriage to you)for what could turn out to be a fantasy. You see the deal is that they are chasing a feeling, not a person, something new & exciting, a feeling that has been missing for a very long time in their lives.
And they know because their husbands are utterly devoted to them, that they can take as long as they want to during this process and that's whats happening to you guys, it's what's happened to alot of us and only a few of us are starting to wake up and realize this.
Regardless if you want to believe it or not, separation is like cancer and is definitely a prelude to divorce. You either nip it in the bud right now or expect to have this last for several months to several years all at your emotional expense - how much are you hurting now after a few months, how about after several months of hoping & pining for her, how about after a year with still hopes of her coming to her senses and still no decision, no movements in a positive direction from her.
All because you have let go of any power you have, you have allowed this to be her decision and not yours and she will do whatever she wants to do now because you are letting her.
I hate saying it like that because I know personally how much it hurts.