Succeed despite your initially being nervous (5)
I believe the answer is:
windy
'nervous' is the definition.
(I've seen this before)
'succeed despite your initially' is the wordplay.
'succeed' becomes 'win' (I've seen this before).
'initially' says to take the initial letters.
The initial letters of 'despite your' is 'dy'.
'win'+'dy'='WINDY'
'being' is the link.
(Other definitions for windy that I've seen before include "The sort of weather" , "far from calm" , "Chicago, the _____ City" , "Timid - tempestuous" , "Gusty" .)