I have to agree. A year and a half with her not willing to respond to the changes means she's got someone else who is fulfilling at least some of her needs.
At the very least, you need to go dark to her and see if she responds to that.
Me: 44, Wife: 39 M: 17 years T: 20 years Bomb on 08/25/09 1/13/10: MC started 1/28/10, 2/8/10: More bombs 8/28/10: Wife moved out No talk of D, no movement