Robx is giving you great advice to allow you to continue to focus on yourself and shift the power. She can't chase you if you are always there. It took me a long time to come to terms with that and it didn't help that a) my head was buried in the sand about her A and b) we were going to MC but obviously that won't work with a 3rd party in the mix.
Don't be affraid of losing her because you already lost her. I am currently filing for legal separation not because I want it but because that is the only way I have to move out of limbo land. I copied the "I get it" quote from Robx's post because I hope someday in the future I will get to use it. As of now my W is avoiding me and not talking about anything.
You can do this. The important thing is to do what is right for you and not to worry about upsetting your W.
M 33 | W 34 | Kids: S4, S3 M: 5/28/05 Bomb: 8/22/09 EA: 8/1/09 | PA 12/26/09 W L: 10/21/09 M L: 11/16/09 | 12/09 to file SA W & Boys Move Out: 3/14/10