@gratia: Don’t take offense to those “friends” who have slivered into oblivion… it’s just that if you are not “seen” you don’t come to mind. Their lives have remained relatively stable, while your life has taken on needed responsibilities and direction.
While you are at the park giving you both some needed change of scenery, be on the look-out for interesting people to pass the time of day with. There are many new friends out there for you to interact with. We can’t change our circumstances but we can adapt and find happiness in so much of life! Find ways to put laughter and happiness into most days.
Best to you…