I just "celebrated" my 3rd anniversary of the bomb. August 27 of 2006 - W flipped a switch in her head.
I still have feelings for her, and I can't imagine a time where I won't - even though I sincerely wish I didn't. I honestly don't want to be married to her - you have to draw a line in the sand at some point, but it's funny that in August of 2006 she was charging into divorce, has started an affair, etc, but I can't get her to sign onto a divorce for the life of me!
I didn't mean to be so harsh before, but seriously the best thing you can do is back away. How far you back away will depend on your circumstances - I spent a full month going completely dark a few months back, and my W didn't even flinch for the full month. It was the hardest thing I've ever done, literally numbing, but it has been the best thing I ever did. What helped me was to literally take things an hour at a time if I had to. I would pick what I was going to do for the next hour, i.e. clean the kitchen, work on a project, make dinner. Then I'd complete that task, and schedule the next hour, and then the day was done. At the end of that month, W was all over me, and I was completely in charge of myself, my emotions, etc.
I don't know the depth of your situation, but I completely understand and empathize with how you feel. I will tell you that my feelings for my W now are much more genuine, and impartial. They are not driven out of a "need" or a clinginess, but out of a desire to do the right thing, and care for her as a person, and are without condition.
Lastly, do find a conversation outlet. The marriage builder person is great - I talked to friends, family, etc. I didn't want to spread out W's dirty laundry, so I found a couple of confidants that I could trust and took the deep things to them - it was crucial in my journey.