Listen, being widely discussed on social media is agonising! (5-7)
I believe the answer is:
heart-rending
'is agonising' is the definition.
(I've seen this before)
'listen being widely discussed on social media' is the wordplay.
'listen' becomes 'hear' (I've seen this before).
'being widely discussed on social media' becomes 'trending' (eg trending on Twitter).
'hear'+'trending'='HEART-RENDING'
(Other definitions for heart-rending that I've seen before include "Causing great sadness or distress" , "Agonisingly sad" , "Poignant" , "moving" , "Greatly distressing" .)