Letter is a bad idea. I know you know this...but we are all tempted to become letter writers, and without fail they all are completely catastrophic. I challenge you to find ONE DBer that said something good came from a 'final appeal' letter.
Get back to believing none of what he says and half of what he does. I get it, I swear I'm not making fun of you. But to think that he actually left because you kicked him out? No. Look at how hard you're fighting for your M. He did more to push you away and you are standing by your M. My point is that nobody walks from a M because their spouse asks them to leave. The walk for one reason: THEY WANT TO. If he says it is about your request then it is because he wants you to feel guilty or hurt, or it is in some other way manipulative. It simply isn't true.
Same with the tumble dry. Could've been habit, temp checking, or who knows what. Don't try to understand someone that is borderline crazy. In order to understand him you'd have to go crazy first and then you'd be no good to anyone.
You don't deserve another chance. You deserve a lifelong commitment. And you don't ever deserve to be cheated on. Unfortunately in this world we don't always get what we deserve.
All I can say is that the first 90 days after BD are just obscenely difficult emotions. Please know they won't continue. It will get easier. Just keep posting, keep venting, and avoid doing anything to make your sitch worse. Survival is the new success.
Me:38 XW:38 T:11 years M:8 years Kids: S14, D11, D7 BD/Move out day: 6/17/14, D final Dec 15