Make Matters Worse Meaning

(idiomatic) To worsen an already difficult situation or unfavourable set of circumstances, typically by acting rashly, foolishly, or incompetently.

Example:   His resentful attitude only made matters worse during the custody proceedings.
2015, Press Association, Wolves rescue point against Hull thanks to Allan McGregor howler (in The Guardian, 16 August 2015)[1]
  The mistake came about when there seemed to be little danger as Dicko swung in an innocuous cross, but the keeper somehow spilled the ball for Henry to head into an empty net. To make matters worse his error came in front of Gordon Strachan, the Scotland manager.