When 'good deeds' do no good, they (idiomatically) '**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.

[Free Dictionary Idioms][1]

[1]:https://idioms.thefreedictionary.com/kill+with+kindness