This might make no sense but I feel the need to vent.
If you were a parent of 7 children, and 3 of your sons had children, and you didn't get to have contact with any of them because either your sons weren't seeing their children or your other sons and their wives didn't want anything to do with you.
Might you question whether actually it's something about your own or your sons behaviour, and not blame the wives and ex girlfriends?