fuck all nothing, eg. sweet f.a to do today sweet fucking Jesus (phrase) ++ expletive with no particular meaning, conveying annoyance, surprise and generally feeling upset about something or somebody. Street jargon without expressedly blasphemical intention. Rather, the expression is more or less generally functionalized as are "fuck" or "shit".
SWEET F.A.
Meaning of SWEET F.A. in English
Slang English vocab. Английский сленговый словарь. 2012