How do you tackle the feeling of "I'm not where I want to be in life"?

I don't really compare myself to others as much as I used to, but this isn't about that.

I'm 27. I've regressed as I've gotten older, I've become more anxious and find it extremely difficult to ask for things when I *need* them, which subsequently gets me into avoidable sticky situations.

I feel like I was expected to know what I wanted to do while I was at school (and I'm probably not alone in that) and I just didn't. I didn't go to university so upon turning 18, I felt completely lost. It was as though the world told me, "you're on your own now, and you're not allowed to ask for help because being an adult means being independent etc". Me, an autistic person, thinking literally? Surely not...

I feel like there's lots of opportunities I missed out on. Whether it be me not asking for help, not networking more, not grabbing things because I was afraid etc. 

I feel like I'm getting on a bit now, and that I've missed my chance. I don't feel you get many opportunities now, and it feels like I'm going to be playing catch-up for the rest of my life.

This is a bit more vent-y than I was going for but it's something I've recently struggled with.