What an idiot Edward is to have helped! (8)
I believe the answer is:
assisted
'helped' is the definition.
('assist' can be a synonym of 'help')
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for assisted that I've seen before include "Helped" , "given help" , "Lent a hand" , "to small sibling involved in stormy dates" , "Aided" .)