Oh hey my depression stairs are like that too, except that there's no chain and the stairs also go down forever into a yawning black abyss. But hey, with enough pills and therapy I can usually mill around in the middle somewhere, and haven't thrown myself off yet.

I get anxious just looking at that staircase

For me, something like this manifests in what I describe as not being able to un-see the big picture, the whole thing from beginning to end. Or, wanting to be able to see things that way. I can’t just blindly take single steps without thinking about and focusing on the endpoint.

And if there’s anything to be concerned about in seeing the big picture, some difficulty ahead I can foresee, or dissatisfaction with where I seen the end result going etc, than that’s what I need to focus on and I don’t understand why people aren’t doing the same.

How else am I supposed to finish on time? Start early? Pfft

Where is this?

To be fair, that advice works on any stairs. It makes no promises on whether you'll achieve it. But it says what it says - one step at a time.