The thing is, not everyone on this forum agrees with the "Be Nice and he will come back" approach when an affair is taking place.
Michele is spot on with the standard wayward spouse who just wants to leave, but when there's an AFFAIR happening, many on this forum think quite differently.
YOUR CONDITION is one of the main reasons why we take this position. Fighting divorce is painful, but bearable. Fighting divorce AND someone deliberately trying to break you and your H up and put an end to your marriage is way too painful for most people to take over long.
Emotional pain will eventually take on a physical form - ulcer, head ache, exhaustion, etc... so when I say painful I mean in every sense of the word.
Myself and others on this forum have reccomended a MUCH different approach than "Be Nice and he will come back"... We reccomend
HIGH EXPOSURE ACTIVE PROTEST COMPLETE PHYSICAL AND EMOTIONAL DETACHMENT
From a cursory scan of your thread it looks like you were using the Davis method rather than the method above.
Keeping in contact with your H, tolerating and befriending the OW, and generally not complaining about the affair and how painful it is isn't in my opinion effective. The only thing you are going to get by doing that is clinical depression and an ulcer.
Sorry, I do not mean any disrespect to MWD or her DB coaches, but affairs are very different animals than a WS.
1. You need to stop talking with OW
2. You need to ACTIVELY and LOUDLY PROTEST the AFFAIR your H is having. Yes, its an affair. By protest I mean you explain to everyone what he's doing AND educate them about how destructive and counterproductive affairs are to reconcilliation. My bet is your community of friends and family are not well educated on affairs. You have read Glass. NOW, its time to make EVERYONE ELSE know who Glass is as well. Reading the book is one thing, but protest means educating your community about what your H and the OW are doing to you and your marriage and your daughter. They are playing the "we're just friends" game and its time to put a stop to it.
You need to confront OW. Normally I would not reccomend this, but in your case you two have established a relationship and you need to clearly and resolutely change the terms of that relationship. You need to meet with her and tell her she is having an affair with your husband, that you are NOT there to argue semantics and listen to excuses. You tell her you want her to distance herself from you, your H, AND your family if she has any respect for you or your family. If she refuses, make it clear she is explicitly admitting to attacking your marriage AND refusing to stop. Then you march away and EXPOSE her refusal. Add fuel to the fire.
Next you tell your H that until he ends contact with OW that you will no longer be in contact with him until she's gone. You WILL be in family therapy discussing reconcilliation efforts on your part, and he is welcome to join you... AFTER she's gone.
Make sure your H has the contact info for your FT so he can make an appointment. Make it clear that if he wants to explore repairing his marriage your FT is who he contacts, not YOU.
Make it clear you do NOT even want to discuss any denial on his part that an emotional or physical affair is taking place. make it clear to him that she's a counterproductive and destructive influence and that he must make a CHOICE - his OW or his marriage and family. He' cannot have both ANYMORE. Then you leave. He WILL try to argue - just leave, don't entertain discussion on the matter. Even if he AGREES with you. Leave... words NOW mean NOTHING. Until she's gone, you don't talk to him, you just act.
Next you STOP contacting your H. You find an intermediary to bring your child to him and to pick your child up again. You do NOT contact him and you BLOCK any efforts he makes to contact YOU. Change your phone #, change your email, etc. Change the locks on your door. Change everything.
Keep up the protest and exposure to friends and family. Go to Family Therapy appointments, and enjoy your life. You don't have to deal with that pesky affair anymore since it is NOW beneath you.
This is a VERY different approach than MWD DB, but in my opinion this is much more effective and less harmful to yourself.