Meat, You and I have something in common, believe it or not. My H was sexually abused. It all came out 8 years ago. I'm not going into detail about what went on in our M then because in involves too much of a violation of his privacy.
I'll share a little of what I went through. He and I had a longer history together when everything came out than you do with your W. That may make all the difference in the world.
I'm going to use the metaphor of your story, 'cause it's a good one. I realized that there was a very strong cord tied around my H's ankle and a troll attached to end of it. My H didn't jump off the edge of the bridge; he was dragged over by the troll. The troll was still exerting a tremendous pull on that cord. My H had to deal with that troll before he could possibly begin to start pulling himself up.
Not having a troll pulling on me, I can't even guess what his experience was like and what he was battling against. I didn't have any control over how or when or what he did to battle that troll. I couldn't even see the battle with the troll.
I did make the decision to stick with him on the bridge. It was the realization that regardless of what happened, he was the one I wanted to go through life with. His troll was my troll. Letting go of that rope and moving on was an option, but it would mean going without him. It was very clear to me that the "without him" part was too high a price.
If you do not feel that way about your W then you need to come to grips with that within yourself. She also needs to know. It may be you need to spend some time with the counselor to figure out how to tell her this, if it is what you decide. You won't have control over her reaction or how she feels about you, but you will have been honest with her about what your limits are, what sort of progress you need to see and how quickly. She won't be operating under any false assumptions on her part.