It is so sad to see a sitch like this.... I feel for you Mandy, my W is exactly where you were before your H found OW. My W says because she hasn't felt that spark for a few years that it means we are not meant to be together. I know I have played my part just like you know now that you played yours.
I can tell you right now that you NEED to detach and be the better option. It has helped my sitch out tremendously. The OW is doing what you should be doing. Be nice, cordial and keep any correspondence short and sweet. But PULL back hard. It's the hardest thing I have ever had to do in my life but it gets easier with time. Just work on you more, this promotion looks promising and a great distraction as well.
I hope my W doesn't have to feel what you are going through right now. I feel your pain and will read your sitch from time to time to see if there is anything I can offer.
Me - 30 W - 28 M 4 t 6 ILYBINILWY #1 Jan - 2011 Band-aid Jan 11' ILYBINILWY #2 7/28/12