Requesting advice my wife's infidelity

Hello. I am at another crossroads in my marriage in which I feel like there is a reasonable chance that by the end of the day I will be going in another direction and separating form my wife. She has a emotional affair 2 years ago and cheated on me this past August while we were separated. We were separated again recently and I just moved back in our home over the weekend and we are trying to save our marriage. I have explained to her that I would not be able to accept any further forms of infertility. Over the weekend I found a letter that she had written to someone that was not named which read "I am so glad that we found each other. I can't wait to see what the future holds for us."

It sounds like she has had no problem moving on with her life and if a woman is seeing another man and she is saying things like that, the end is near. Idk why she is prolonging the marriage but I suggest that you do what's best for you. She clearly is not making an effort to save yalls marriage. Two people have to save a marriage and it looks like you only have one person trying. I wish she wasn't a cheater and I'm sure you know in your heart you don't deserve that, but she has an issue of commitment and that is beyond your control. I say get out while you can when she isn't bitter and take as much of your crap as you can before her and some other man do.