The Shite That Falls From Clouds.

[Leanne]

Nightmare dreams precipitate:
Our thunderous thoughts collected;
and with the waking hours done
in sleep we're resurrected.

Through the maelstrom, run boy run
escape is not a given
once the carousel has spun
we surely will be riven. -- this line is awkward, though metrically sound -- what about "we'll certainly be riven"?

Split asunder torn apart -- a comma would help after asunder
from one horrendous killing; -- "from" or "by"?
till anew the next one starts
and blood afresh starts spilling.

A lifetime's skies can't hide us. -- you miss a foot here, you could try "a lifetime's skies, they can't hide us"
We fail; fall into the crowd -- here you add a foot, maybe "we fail, fall through the crowd"
hit the pavement with a cuss; -- "and" would help at the start of this line
catch our breath and cry out loud. -- I'd be tempted to split this line into two, a variant won't hurt:

catch our breath
cry out loud

Aside from losing your metric mojo in the last stanza, you've put a bloody good poem together here. What are you whinging about?