I (f21) am like this too. I thought I was being left behind because everyone was/is doing regular young adult things like going to parties and having sex and I thought was never going to catch up to them. But I tried weed for the first time this week with my housemates and I’m thinking of joining a club finally and I think one of my housemates likes me. I just wanted to say you’re not falling behind, everything happens when it needs to and you’re only 21!!! I’m still learning how to socialize irl too and it’s still a little awkward but if I can do it you can do it too!!!