The absolute best thing for me was having a grandson at 63. I retired at 66 and my husband was killed in an accident six months later, having never retired. I stayed busy for many years taking my grandson to playgrounds, to a swimming pool (where I got exercise too) out to lunch, to movies, an occasional out of town trip, camp, cub scouts etc. He was with me more than anyone else....I even went back to church after years out so I could take him to Sunday School. Now I am 79 and he is 16 and I am feeling what you are feeling. I think you should see a psychologist or social worker too....but your grandkids would want you around if you were committed to enriching their lives. If you are sad and not focusing on them, that won't work. I was heartbroken as a widow when I was alone, but my sweet grandson kept me going. I don't see him as much, but I never turn down a chance to take him to school or pick him up. I show up for any school events and do what I can to stay in touch despite his devotion to his computer. If your grandkids don't respond, maybe find a way to spend time with kids in need of a person who cares....kids will help.