I won't give up (An ErrorMare FanFic)

Error is dating Ink, until an heated argument separates them. Error goes to his best friend Nightmare for help and a place to stay. Nightmare--having secretly been in love with Error--gladly accepts and Error moves in. The gang is untrusting of him since he turned on them to work with Ink in the past.
Things repair themselves with time and reluctance, but something sinister is working it's way to the surface. Something evil plans to take everything Error cares about -and more-and render it useless. The Bad Sanses must band together with others to stop this before everyone is hurt.
But how?