When 'good deeds' do no good, they (idiomatically) 'kill with kindness'.
Kill with kindness : Overwhelm or harm someone with mistaken or excessive benevolence.
For example, Aunt Mary constantly sends Jane chocolates and cake and other goodies, even though she's been told Jane's on a diet-nothing like killing with kindness . This expression originated as kill with kindness as fond apes do their young (presumably crushing them to death in a hug) and was a proverb by the mid-1500s.