Islander, Sorry I am late to the party, but I just got caught up on your sitch. Let me just throw in a few points. Denver and Grocery have nailed it. Listen to them.
But, just a few things to think about:
1) DON'T SEND THE LETTER. I know you said you wouldn't, but I want to make sure you don't change your mind later. DON'T SEND THE LETTER! I can tell you this because I did send my letter and it went awful. The entire point of the letter was missed completely by my W and she responded with a horrible letter that crushed my soul. Nothing good will come from this letter. Here is what my C told me to do and I think it is sound advice. Whenever you feel the need to write a letter to her, do it. Put whatever you want in there. Curse, spit, cry, yell, it doesn't matter, write what you feel. Then put the letter in a box and hide the box where no one can find it. Writing the letter will get these feelings off your chest but they can't do any damage sitting in that box.
2) Don't do anything to relieve her of her guilt. I have been preaching this all night. Listen to me, man. SHE LEFT YOU AND YOU DON'T OWE HER ANYTHING! If she feels guilty, GOOD. Let her have to sit neck deep in this sh*t she has doled out. If she can't eat b/c of the guilt, good. Is she can't sleep b/c of the guilt, good. She has done nothing to relieve you of your pain, so there is no need to help her with hers.
3) Don't confront the OM. That will also go badly. Nothing good will come from it. Don't contact his W either. Nothing good will come from that in any situation. You could find yourself in some deep trouble. Two wrongs don't make a right.
4) Yes, going dark is hard. Very, very hard. But, listen to Denver. It works. I had to go dark with my W for six weeks. In 15 years together, we never went more than 24 hours without speaking to each other. It will work. She needs to feel that fear that you could be walking away also. Don't shelter her from that fear.
5) Good job on delaying the lunch. But remember this while you are there. Don't talk about R. Smile, be polite, "acknowledge and apologize," and do nothing else. Don't ask for another date soon and don't talk about the future unless it is you telling her about something you are going to do.
Keep up the good work! Yes, it is dark right now and it probably feels like the walls are closing in on you. I was there a few months ago. But, there are brighter days ahead, I promise.
BITS never walk alone!
FOBD
Me: 39 W: 36 T: 15 yrs M: 9 yrs S: 09/10
So you can get on with your search, baby And I can get on with mine And maybe someday we will find, That it wasn't really wasted time...