I know the advice I am about to give is not as easy to do as it is for me to say it, but don't dismiss it out of hand. Stop worrying about how others will perceive you, and just be yourself. You needn't totally change your personality and become an extrovert, but stop fearing just being yourself. Yes, there are those, and they might even be a majority, who will avoid you or be uncomfortable around you, but you will be surprised that a few will be interested in getting to know you without you having to put out ads, or posing as something you are not. I would recommend Susan Cain's book Quiet about how to get along as an introvert in what has become a society emphasizing extroverts.

As for dying alone -- I suspect that happens to the vast majority of us. Despite all the obits referring to "passing away surrounded by friends and family", that has not been my experience. And I have now been there for the passing of two partners, as well as having been associated with the passing of my parents and other family members. Even when physically there to see them take their last breaths, they have been so comatose as to be alone in their passage. No last words, no "rosebud" escaping their lips.