Believe it or not, even with a mate and kids, we can feel quite alone and our task is how to carry on. Kids are far away, mate has his own interests. Goes on motor trips while I can't abide the road. No extended family, no close friends.
I live in terror of what the end can bring (disability, dementia, etc.) and so am always on the look out re getting out before the sky falls in. In the meantime I have my interests, activities, efforts to over come anxiety, fear, worries, depression, etc. Learned CBT and ACT. Like being a student of human nature and our psyche. Perhaps we are just loners. My early years point to that. Nothing wrong with it, really, except as we are judged otherwise by others. We like to march to our own drum.