Honestly, I have always felt the same way. I’m a teacher, another female-dominated profession, and I often don’t feel like I fit in. In my situation, my colleagues are all great and friendly toward me and I to them, but the trouble is that I personally have social anxiety due to my ADHD that makes it hard for me to get to know them more. When I was a kid, I was bullied all through elementary and middle school. In high school, my peers isolated me because I was the “oddball,” and really, I isolated myself because of the pain from being bullied my entire life and from low self esteem from it.
I wasn’t diagnosed with ADHD until two years ago this month, and while it was a relief to know that my shortcomings weren’t *entirely* my fault, I also knew that for me personally, it would always be a contributing factor as to why I don’t and won’t ever have many friends. That being said, in some ways, I kind of prefer not having many friends. People are exhausting, and while it’s fun to socialize, I can only handle being around one or two people at a time. Large groups of people make me nervous and self-conscious, and I just don’t have the mental energy to continually monitor and analyze everything I say and do around people.
I, too, have seen some of my close friends have outings, and sometimes it does bother me that I wasn’t invited, especially since most of my friends are now aware I have ADHD and my social ungraces aren’t entirely my fault. I think in your case, if you want to get to know your colleagues, why not try putting yourself out there and maybe start by offering one colleague you know you get along with an outing to lunch or coffee. Try having an outing with one or two people at a time in a calm setting that isn’t as likely to excite your ADHD and give them a chance to get to know you better and see your good qualities.
As far as people saying they don’t know if you’re joking or not, ADHD affects the way we socialize, and we don’t pick up on social cues like a neurotypical person. You might want to simply offer an apology if you have done anything to offend them, that it wasn’t your intention, and that you’re working on your social game. I have a friend of mine who is an aircraft mechanic with ADHD (don’t worry, he’s a GREAT mechanic and pilot), and he gets told the very same thing. He is kind of a smart ass, but he’s also funny as hell. He usually will come out and say, “I’m just joking” if he really is joking.