I have this issue as well I used to put way too much into maintaining friendships only to have people take advantage of my kindness and naivety or maybe I unknowingly break some social rule and people don't find it acceptable now I'm just quiet and don't bother to try making friends anymore but it's sometimes extremely lonely. It's hard because a lot of women mainly like to talk about relationship/friendships/family and I don't really have much of that to talk about. I tend to like doing activities more than talking anyways. Most of my friends growing up were really into art/stem but like you've experienced, they usually have their own little circle or keep to themselves. I also like male-oriented hobbies but it's never just friends with men. Guess I still have my SO and a cat. The closest real friend I've ever had was actually another girl in hs with adhd lol.