Seamstresses: you are not a sewer.

Sewer:
an ​artificial ​passage or ​pipe, usually ​underground, that ​carries ​waste and used ​water from ​sinks and ​toilets away from ​buildings to a ​place where they can be ​safely ​gotten ​ridof:The ​county is putting in new sewers.

(Definition of sewer from the Cambridge Academic Content Dictionary © Cambridge University Press)

This is not you.

I've seen also "sewist," which I find to be an ugly term, but at least it avoids calling oneself a pipeline for excrement. My mother once called my father a "fine seamster" when he mended a jacket. "Seamster" makes more sense as the counterpart of "seamstress." Merriam-Webster seems to agree, though my blog platform here is underlining it in red, telling me to knock it off with the funny words. As I type, I see the red squiggly line underneath "sewist" as well. So you're either a seamstress, or a man who sews. I guess you can call yourself a "seamster" as long as you carry a copy of Merriam-Webster around with you. But neither of you, please to God, is a sewer.