the big secret

My whole entire family knows that my mother has  Alzheimer's disease. my brothers sister know but they chose not to acknowledge it openly  It is never talk about as a family.  My father protects my mother at all costs.  I know they have been married 62 years I know how much he loved her.  But I myself am beginning to lose touch with what is  real.  Everyone says just go along with what she says because she will not remember it in an hour.  I am the only one she talks to.  Sometimes she speaks of killing herself.  She speak to me because I am her only friend now.  Sure there's my father but she does want to upset him.  I constantly fighting back the tears because I can't handle my own life much less my mother's.