I know completely how you feel! I honestly almost posted something similar to this yesterday! I feel like I am stuck in childhood. I do not have interest in any adult things, and I believe that is why I can never make friends, or hang out with people younger than me. I do not know why I feel this way, or why you feel this way, but I just try to enjoy the way I am, even if nobody my age is the same way. It is okay to not act emotionally like a grown-up. My advice is to try something new. Even if the new thing feels strange because it is outside of your "norm," just try it to see if you feel any different. I am always here to talk if you need anything.