Loud American with a pimple worries too much (7)
I believe the answer is:
fusspot
'loud american with a pimple worries too much' is the definition.
I can't tell whether this definition defines the answer.
'loud american with a pimple' is the wordplay.
'loud' becomes 'f' (short for forte - 'loud' in music).
'american' becomes 'US' (United States).
'with' says to put letters next to each other.
'a pimple' becomes 'spot' (I've seen this before).
'f'+'us'+'spot'='FUSSPOT'
Can you help me to learn more?
(Other definitions for fusspot that I've seen before include "Perfectionist" , "Pernickety person" , "one worrying about trifles" , "One who worries too much" , "Hard-to-please person" .)