"You're going down" sounds like something you say to someone right before you punch them in the face (which is not what the Swedish sentence is refering to), I think a better translation would be "you are (currently) heading down(wards)"
Xini,
I'm aware of those suggestions, but as you know, it's quite difficult to translate such a short sentence if we lack a broader context.
We can't guess its exact meaning.
Since the English was correct, a poll was set to evaluate its meaning.
It was supported by most of the Swedish users, otherwise it wouldn't have been accepted.