If it means what I think it means, it predates the internet.
Manure Out of Luck (only the word that begins with S meaning manure)
Scritzy's right.
And, it's not an internet abbreviation - I'm surprised you haven't heard it in real life as well!
Thanks for the help folks - it was so frustrating!
I have heard it in real life... just not the abbreviation. We use the full phrase

So I'm afraid I just didn't make the connection!
And I have rarely heard snafu'd contain the would 'fouled'. I think if people have a need to spell it out, but don't use profanity, they tend to say "all f'd up".
The best translation from the profane I have heard was:
"I'll just get my poo's in a pile"
I used to use it - bit DH couldn't stand it as he said it sounded gross. So now I'm back to getting my s*** together. Sigh.