>>529511302
I was half-joking, but if you were to look at your situation through the lens of autism your problems would make perfect sense still;
being autistic doesn't mean you can't learn social skills through trial&error, but it means that you're likely to build up your social skills to say the "right" things instead of saying the things you really feel because those tend to put people off, especially when growing up which builds up your patterns of behavior for adulthood

the reason why they lose interest could be a hundred things: once you get comfortable you act too negative, you start talking about yourself more and the friendship was built on you asking about their interests instead of their interest in you, you start saying more and they struggle to really keep up with what you're saying, etc.
I hope it's not actually autism, but there's always a reason for why patterns form and there's (often painful)ways to alter them if you're willing to look at things from different angles