frightmare

noun2

1. •
   An extremely unpleasant and frightening experience.

   • Yes, that must have been the way it had happened, Gibby decided — just one long frightmare, part of it filmed in this bedroom. — 1974
2. •
   (informal) Someone or something extremely unattractive.

   • Try and stick to only a few decorative elements, not a 'more is more' frightmare. — 2011