I'm something more than twice your age, and have felt the same way you do now. I've spent countless hours "keeping up" - lost a marriage in part due to this - and there is always stuff I don't know and am curious about. There is always someone more knowledgable, or faster at coding, or better at interpreting requirements. That's one reason I like working with smart, capable people-there's always something to learn from them. I've lived through marathon coding sessions, death march projects, been a manager, been an employee and been a contractor.

I don't care to keep up on everything any more. I remain intensely curious and "keep up" in a general fashion, reading articles, playing with code samples etc with an eye to being able to converse with my colleagues about what they're doing, not with the idea that we're competing to be the alpha geek.

Some of the other posters here have suggested you find something you're actually interested in and spend time on that, or that you find cause you can volunteer for and to that. Those are good suggestions. Find something outside your head you can do and commit to it. Part of your anxiety is because your world is narrowing because of the concentration on what is in reality a little area and you see others doing "better", whatever that means to you. Get out of that world for a bit.

Understand that time will pass and whatever technologies you get to know well will pass out of the market sweet spot. Maybe you'll be ready for that and maybe you won't. The question is will you have enjoyed your life when you realize this? Tech is a tool. One you use to make a living, one your employers of whatever stripe will try to use to make money. It is not a reason to get up and breathe.