Any lights on the dash?
Was full power restored?
Any odd noises when you tried to accelerate?
Any intermittent hiccups before this?
Could really be any number of things; limp mode, misfire, fuel cut, the list goes on. You need to get it scanned first. If you can find a forum member with VCDS that'll take a tenner for their help it'd be a good start.
If there aren't any fault codes stored a little live logging session with VCDS will scratch the surface further.
Until then it's guesswork. If the fault hasn't cleared I'd advise keeping the driving to a minimum and make a scan your priority. If you need help deciphering codes there are plenty of knowledgeable bods on here.
ETA: Have a look around the engine to see if anything looks amiss; hoses, lines etc. Could be you've popped off a boost pipe or something.