It’s a natural thing for adult children to do, they need their own life, their own ways and their independence unfortunately some grandparents don’t have a life outside their family then when that family wants to become independent, their world drops to pieces
You have no right to expect your adult family to live around you. You should be applauding them for having your own life and doing it their way. You need to extend your own life. Find things to do, hobbies, places to go, groups to join, voluntary work, new friends, take more time with your partner if you have one and generally get on with life, children and grandchildren are not there to be your amusement
Your life and your happiness cant be built on others you have to find your own life