Abusing Oprah, Sting, Lennon endlessly? Don't take it to heart (7,8)
I believe the answer is:
nothing personal
'don't take it to heart' is the definition.
(both might be said to console someone)
'abusing oprah sting lennon endlessly?' is the wordplay.
'abusing' is an anagram indicator (I've seen 'abused' mean this).
'endlessly?' means to remove the last letter (I've seen 'endlessly' mean this).
'oprah'+'sting'+'lennon'='oprahstinglennon'
'oprahstinglennon' with its final letter removed is 'oprahstinglenno'.
'oprahstinglenno' is an anagram of 'NOTHING PERSONAL'.
(Another definition for nothing personal that I've seen is " don't take offence".)