Fixer So agree w/ Fig. You've heard it over and over I am sure that a loving parent(s) is what your D needs, that may be together or it may be seperate, but two happy , loving parents will help your D in growing up. She will know if you decide not to stay married to your W that you did try everything , up and beyond to keep it together, don't worry that she will think negative of you in anyway. Ask any of us in S, our children know we tried everything, they respect us for that, your D will too. She will be fine if you decide to a different route.
Good Luck Fixer
Be Happy for this Moment, This Moment is your Life