Visitation cut off/limited. Any suggestions?

I am the mother of a 20 yr-old-daughter that is terminal with a Glioblastoma brain cancer. At her diagnosis over a year ago my ex mother in law wheedled her way in and became her primary caregiver and went as far as to hire an attorney to write up POA and DNR for my daughter. She claims that the decision to not allow me to see my daughter (who is like my right hand) was all my daughters idea and she is respectful of her wishes. She blocks my phone calls, has told all of my family they aren’t “on the approved list “ to come see Amber. She refuses to allow me to be by my daughters side. Claims I’m a disturbance to My daughters well-being. On many occasion my daughter has been left In Tears after I’m kicked out from visiting with her after 10 minutes. I can’t speak to hospice as ex mil set up a code word with them and if not provided they won’t talk to me or anyone else. I hate this woman more than the air I breathe. I literally have NO ONE that will help to get her to see things normally and allow me and my daughter's family to support her and be by her side to say goodbye. This has been going on since June last year. The ex mil is a covert Narcissist and rich so she has everyone snowed with her victim behaviors and uses her money to buy everyone off. Please someone help me with some solutions.