It seems you don't hold her to any standard as a mature, loving partner, except to have sex with you. Maybe that's too harsh but you seem quite happy to act like a parent in the relationship -- she doesn't have to do anything that most normal, mature adults have to do. If she sees you as a parent figure, someone who takes care of her rather than someone who is a partner, that is sure to kill her sex drive for you.
I think you do have to deal w/ her infatuation with the celebrity, but you have to think about whether that's a symptom or a cause. I would guess that even if you confronted her and she was sorry, the problems in your marriage will remain. She's looking for something that your marriage is not giving her.
Me: 50, MLC/WW 45 Young kids Nov 2015: BD1 Apr 2016: BD2 Jan 2017: W filed Feb 2017: D final