I am sorry you are struggling. Honestly it is pretty common for strangers to not listen to other people stories or not respond to random comments .

Baristas and store clerks are not really acquaintances , they are just doing their jobs ( unless you know them outside of their jobs), it is understandable they are not engaging in conversations beyond common courtesy.

Those people that you see comfortably chatting aren't doing it with strangers. They are doing it with people they know.

Have you tried meetup groups as I previously suggested? You can share with them. I am having meetup even this Friday night and then following Sunday. Why dont you try that? Also would you consider having a part time job just to keep busy? You said you are retired, but many retired people keep part time jobs. Having too much free time could be detrimental or did you try to volunteer? Hospital? Nursing home? Shelter?

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