I know complications are important, but I always feel bad about making my protagonist go through terrible things (unless I don't particularly like them, I suppose. Then I want them to go through more hard things. ) It can be challenging to come up with complications. If you're having a hard time, you might consider some of these questions:

What's the worst thing that could happen to my character right now? (No matter how ridiculous- worry about how it applies to the overarching plot in a second if your first thought is "an asteroid crash lands into their face" or something )

What's the second worst thing that could happen to my character right now? (Might help steer your brain away from the asteroid... )

If something happened to y character, how would it affect my protagonist? (Things don't have to directly happen to your protagonist, after all. Supporting characters have bad days, too.)

What if something bad happened to my antagonist? (If it does, how does that affect my protagonist? How can I make any "supposedly good thing" actually become a bad thing or a complicated problem for my protagonist?)

What if a second asteroid crash la-

Maybe not that one.

Also consider- how does it feel like the universe is conspiring against this character (even if it's not true)? Because I'm sure everyone has those moments where it feels like that's what's going on, make your characters have those moments, too!

"Whoever fights monsters should see to it that in the process he does not become a monster. And when you look long into the abyss, the abyss also looks into you."-Nietzsche