Losing the thread

[Wjames]

calm in all its continuity I naturally pause here when I read this, so you might want to add some punctuation.
a loose thread through time
not taut

so easily slackens into
flickering shapes of
_____________unease
I don't have a problem with flickering. I don't like the use of "slackens" here however, it literally means "relax, or loosen" but you're using in the opposite manner (to depict unease). If this were my poem, I would have the thread tighten into stiff spines of unease in contrast to the looseness of calm. In the first stanza I already get an image of a thread gently "flickering" to depict calm so using that same image (only more violently) to depict unease is kind of confusing.

I like your idea of a string as a metaphor for calm, but think it could be better executed (you're free to disagree).

Just write for yourself, and if others like your stuff too, that's great. Otherwise you'll spend too much time worrying about how to please everyone but yourself. If someone offers you critique you like then use it, but if you disagree with it don't let it wrankle you. Welcome to the site.