In short, is there something I’m missing here, or is work-eat-sleep-repeat all there is until I retire?

You might die before then. I definitely saw “bottlenecks” in my mid-20s and late-40s where friends dropped like flies and some never got back up again.

Anyway, it sounds like you are having a crisis - people talk about the mid-life crisis but they can happen at any age but often a turning point:

• Late teens - wait! I have to grow up and get serious?
• End of Uni - wait! I have to get a job and all that other adult nonsense?
• 30 - wait! I should really be married and having kids by now.
• 40 - wait! My biological clock is ticking, I haven’t been promoted like I thought I would and my body is starting to creak.
• 50 - well that didn’t turn out how I wanted but there’s still time.
• 60 - where did my life go? Ah well, retirement is looming, I can’t wait for all that free time.
• 70 - death is looming, where did all that free time go?

Unfortunately, the meaning of life is what you make of it, so start managing your expectations.

I can’t claim to have any clear answers but find.out what you love doing and build your life around doing more of that. Don’t let your worklife eat into your personal time. Stop caring what people think about you, but that’s not a license to be a dick. Make the world a better place for having you in it. If you need help, ask. Eat well, don’t smoke, drink in moderation and wear sunblock - these things will help your later life be more worthwhile.