Cant Relate To People Anymore

Im 37 yrs old and for about 30 of those I use to have heaps of friends and was a very social person. I played in bands, surfed all the time, went out to pubs and clubs about 3 times a week and could talk to anyone I may have run into in my day.
Now, completely different story. I have only 1 friend left, apart from people I work with and have the worst social anxiety ever.
I feel as though I cannot relate to people and the small talk chit chat bullshit that most people engage in each day. It seems so pointless to me.
When I do try to involve, I am overcome with crippling social anxiety that penetrates my will to speak. Nothing comes into my head that I can say.
Because of my feeling so awkward now in situations like this, I can feel a negative energy coming off me and people pick up on it and get the wrong impression of me.
Now I'll just do anything I can to not engage in any form of social activity just to avoid that feeling altogether. Im kinda getting use to the idea of being a bit of a loner but am also envious of seeing other people socialise without a second thought.
I do miss having friends but don't know now if I could really do it all now.