I have been reading your thread and want you to know that I really admire the lengths you have gone to for your marriage. That said, I will cut to the chase and say, "please listen to AmyC." I am afraid that you will lose yourself completely if you keep letting your W call the shots here.
Please, if you haven't already, go look at my thread in "Separated." It has some stuff in there about being able to let go. Trust me, I know how you feel. I have been fighting my H's decision to leave the marriage because I knew (still do know) that he would come to regret it later. But, Frank, I have to let go and let him experience this all for himself. By telling your W that you love her and always will, you are just making her more determined to show you why you are wrong. You have to let go and show her that you have faith in her decision making processes. And, that means that until you ask her to leave (and I really hope you do at some point), the old mattress is HER CHOICE. Quit saving her.
Like you, I want to believe that my marriage will be saved. But, my H isn't on that page with me. I can't force him there. I can't force the "love is a choice" theory anymore. He needs to live it. I have been just as guilty as you at not making my spouse live with his choices. I have been bending over backwards, hoping that he will see what a great person I am.
I've shown him. He knows it. Now, he needs to miss it.
Hope you will visit my thread. Betsey and H2H have lots of good stuff on there.