I am also in my late 20s and feel the exact same way. I feel socially stunted. I find small talk so difficult and I haven’t had a friend since I was 16. I have spent the last 12 years on my own. I never made any connections or had any romance. I feel as if I was invisible for most of my 20s and now that 30 is approaching I have lots of regrets. It sucks. I don’t know what advice to give, but I just wanted to say your not alone in this.