Welcome Gigi.  My marriage was "only" about 28 years, not 45 like yours, but I too have two alienated adult children due to the continued denial and lies, as you have noted in your situation.  This alienation of adult children is something that appears to not be uncommon, but it isn't something that is a regular topic on this forum.  On the old forum there were a couple of other women in this situation also.  For me it is the absolute worst part of this thing and one thing I cannot reconcile or get over.  

I also wonder sometimes if some of those on this forum with young, minor children won't eventually encounter this problem some day when their children do become adults.  Also, most of what I have heard about this issue involves daughters and straight mothers.  I have not really heard about other combinations of parents and children that have this problem.  It might be something fairly unique to some mothers and daughters who find themselves in this situation.  It seems like the fathers in these cases just continue to deny and lie to the children and the daughters continue to maintain a sort of hero worship about their fathers and want to "defend" against the mother who as "wronged" their father, according to what they have been told.

I am always open to hearing more about other women in this extremely painful and difficult situation.

I am sorry that you too are experiencing this.

Lake Breeze..........Throughout my childrens' lives, I was always their confidant and the one they loved and valued, knowing Mommy would always support, advise and love them.  All the sperm donor did was side with them when I would find the need to discipline them.  He never had my back, which is common with toxic narcs.  hE likeD to be their hero, And he would always chastise them for coming to me for advice and assistance....................WHILE HE PROVIDED NONE OF THAT!!!!!!!   Go Figure.

Kel,
Thanx for welcoming me!!!   I am so pleased that your children "finally saw the light"   That surely must have relieved the terrrible pain YOU were dealing with.  Unfortunately, he has my children thinking I'm paranoid.  I should have voiced my suspicions years ago, while I was still in denial.  When all the pieces finally came together for me and confided in them, they just couldn't believe what I was saying.  My one adult child told the other.... either Mommy's going crazy or Daddy is the biggest liar in the world.  IF ONLY I WAS LYING!!!!

Gigi- Your comment above about your children sounds very close to what I have experienced.  In my case though, he would not chastise them for coming to me for advice while they were growing up, he would in fact encourage it, but then he would negate a lot of what I would tell them, with such comments as, "you wouldn't HAVE TO do it that way!" or "maybe some people would do that, but not EVERYBODY".  Mine never had my back either and would often "side" with the kids if I put my foot down about how late they could stay out, or school/social life balance issues, etc.  Unfortunately it all continues ...