Since I've been diagnosed I'm acting more childish

I've always acted very immature for my age (26) but since I've been diagnosed I'm being really childish, especially when I'm alone or with my mom. I think my real age is 3 years old sometimes because why am I acting like this. I know it's wrong this is why I don't do it when I'm with friends but sometimes I want to sometimes I really want to be a little kid and don't have to worry about anything, but I can't. I need to grow up and I need to do it fast but I becoming younger