But that's the thing, most people say you cannot change your personality, and that trying to do so will make you come off as fake and manufactured.

I would not say that nobody likes me. Lots of people do. But that's besides the point. It is possible for people to "like" you and still see you as a loser.

And are you suggesting that people only dislike you if you are mean and nasty and that if you are nice, they will like you? Because that has not been my experience at all. In my experience, you could be the nicest person on the planet, but if people perceive as dumb or awkward, they will often dislike you. Not everyone, there are some people who are not judgmental, but lots of people. Especially young people. I typically avoid this because I tend to not put myself out there around most people. But sometimes my awkwardness and "ditziness" shine through and it seems to really annoy some people.

Have you seen the new Ghostbusters movie? The way the characters respond to the character Kevin is such a good example of what I am talking about. He is basically this really good looking guy who turns out to be extremely dumb and clumsy. The ladies in the movie can't stand him. It was actually uncomfortable for me to watch because I identified so much with him and his social interactions. He is not "unlikable", "disagreeable" or "nasty", he is just slow. And people don't like that. My social awkwardness might be because of social anxiety, but the social anxiety is brought on by the rational fear of coming off as dumb and being disliked.