Go off and leave you thoroughly confused (5)
I believe the answer is:
addle
'go off' is the definition.
(eg an egg might addle)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for addle that I've seen before include "Muddle or confuse" , "Get rotten" , "Go rotten" , "Mix up or confuse" , "Confuse; go off" .)