It sounds like you love your daughter very much, and you have concern for your relationship with her. It is an emotional roller coaster when a family splits up, especially when there are children involved
My parents separated when I was a teenager...my dad would try to talk with me about the "separation." He talked about his confusion and his love for my mom, etc...
Within the first 10 seconds, I would feel my stomach turning, and then my head pounding, kind of like a volcano!!! There were times I felt I would vomit...
Being a teenager is a confusing time for kids...and parents no longer together...their world is changed forever...in addition to their identity crisis...nothing is stable.
Anytime a family breaks up and there are children involved, it is a tragedy. IMO, I believe that it is the responsibility of the adults in the situation to support the children emotionally. Everyone, including the children, should be in counseling learning new coping skills, communication skills, figuring out how they fit into the new world around them and having that one person (who is unrelated) to share all the yuck that comes with divorce/separation.
I'm sorry to hear that you are in such a difficult spot...now that I'm going through my own divorce (with children), I can understand my parents much better. It is tough...but I hear (and believe) once we get through the s*@# of divorce, the emotional stuff gets easier.
I hope your daughter is able to eventually find compassion, and that someday your relationship will be healed. It took awhile, but my dad is still my hero!