I think that real friendship is based on many joint memories, so it (well for me) has become impossible to make new friends. Six months before I retired my second best friend died, and then six months after I retired my very best friend. I found it all extremely difficult (and, yes, it was about me!!). All the things we had planned to do when I retired disappeared.
I set out determined to make new friends and joined so many different local organisations. However, it was not to be - make lots of new aquaintances - but no friends. No-one I could just pop in when I felt down, or get them to come to me. I have now accepted this situation. Still have one friend whom I see about once a month. I have things I attend most days, but feel that the time for real friendships is long past.
One of my children still loves near me, and I usually have her and her daughter for a meal a couple of times a month. I do long weekends away visiting my other children and g.children.
So miss my bestie (even after nearly eight years), she and I would have a long phone call each evening, usually happily moaning about our children, etc. We had met when we were expecting our first babies and remained close friends for forty years. We knew things about each other that even our husbands did not. Nothing can ever replace that or fill that void.
Most of the time I am fine, but I do get lonely at times, even when I am surrounded by people. But have come to terms with the fact that friends are now a thing of the past.