I’m impatient and always drink to stay bluff (3,8,4)
I believe the answer is:
for goodness sake
'i'm impatient' is the definition.
(phrase said in impatience)
'always drink to stay bluff' is the wordplay.
'always' becomes 'forgood' (for good can mean permanently or forever).
'drink' becomes 'sake' (sake is a kind of drink).
'to' says to put letters next to each other (I've seen this in other clues).
'stay bluff' becomes 'ness' (I can't justify this - if you can you should give a lot more credence to this answer).
'sake' after 'ness' is 'nesssake'.
'forgood'+'nesssake'='FOR GOODNESS SAKE'
'and' is the link.
Can you help me to learn more?
(Other definitions for for goodness sake that I've seen before include "Really!" , "Words of exasperation" , "please!" .)