I wouldn't worry about the letter and what he's saying. If you are above it all, stay positive and friendly everyone (including him-- although maybe not until some future time) will realize you are not that way. If you complain or try and defend yourself everyone will associate you with the negative. My husband did the same thing (actually for a long time). In detaching I finally learned to not take his rantings and criticisms personally and even find some humor in the whole thing. I also learned that for him to really appreciate me, he actually needed to be around OW and meet various women to learn that I wasn't so bad. (Sheesh!!! we are ALL hormonal, difficult to deal with, moody b!tches!!!)
In time eventually he'll see OW's negative characteristics. Right now he's probably only seeing the good characteristics. I'm sure she's very careful not to show anything negative.. and I'm sure he's doing the same. That's what we do when we first meet people we like. We want to be accepted so we're very careful to only show the positive... but at some point everyone's positive and negative qualities become obvious.
Also, keep in mind your husband may be getting a lot of flack from others about how he's treating you. He probably feels compelled to show you in a negative light to defind himself. He may not even really believe it, but he's trying to cover his butt and not look so bad. Eventually he'll see what he's doing. It will take time, but he will. I've seen this before....
P.s. I'll try and email you this morning. I don't know why the PMs always say full. Do they even work? Does anyone send or get them? Is this because I have a Mac?
There is no arriving, ever. It is all a continual becoming.