Beside myself again with fury (3)
I believe the answer is:
ire
'fury' is the definition.
(ire is intense rage)
'beside myself again' is the wordplay.
'beside' says to put letters next to each other.
'myself' becomes 'i' ().
'again' becomes 're' (prefix meaning 'again').
'i'+'re' is 'IRE'.
'with' is the link.
(Other definitions for ire that I've seen before include "Strong feeling" , "passion" , "Outrage" , "Anger among admirers" , "Hot temper" .)