actually It sounds better :: buried six feet under.
It is thought provoking that You searching for flaws in you getting you under. I am sure it could be the case in some bipolar or schizophrenia, or some masochistic situation. Still I rank it poetical.

Hmm… no, looking for flaws are meant to be a means to improve. The problem is when we end up finding too much flaws. I just went along with the ending and force it. I meant to write under but I needed a reminder that that’s not exactly the ending that’s needed. It needs to sound off.

Of course when we are looking for flaws, specially in ourself, we are trying to improve ourself. It goes into manic state when we get obsessed with it. and turn it to self harm.
But I think when we go that deep, we should be carful or do it with a nahual or guru in order to avoid harming ourself six feet under, as you nicely put.

I don't really get the difference you see between under and down. Unless you avoiding to sound so ominous.