Behind it, I become self-conscious (9)
I believe the answer is:
inhibited
'self-conscious' is the definition.
(thesaurus)
'behind it i become' is the wordplay.
'become' is an anagram indicator.
'behind'+'it'+'i'='behinditi'
'behinditi' anagrammed gives 'INHIBITED'.
(Other definitions for inhibited that I've seen before include "Constrained" , "Guarded" , "Hindered, restrained" , "Hindered (an action)" , "Be hid in it (anag.)" .)