I went through the same process of losing confidence. It began around 11 or 12. I'd always been athletic but I lost confidence in that, too, once I realized as a girl I'd have few real options for sports (this was in the 80s). I always attributed my problems to being a tomboy but there was more to it than that. I just didn't grasp social games, so much so that I didn't even know what I was missing--I just had a vague sense something was wrong. Now I'm in retirement, surrounded by neurotypicals, and I seek out people more likely to be neurodivergent, people in the LGBTQIA community. I still feel like I'm hiding, because trying to explain or "come out" about autism and ADHD and giftedness is easy online but in real life, people just get confused or else tag you as disabled. Like you, I'm grateful I have a few close people who are neurodivergent too and/or can understand, but social events bring me no joy.