First thing I would do is to check for boost leaks, then have it scanned if nothing obvious.
Do all the cheap things first.
If the throttle body is dieing it will eventually flag the old EPC warning light, then the TB is goosed its usually the potentiometers g187/188 inside rather than being gummed up, a scan will show this, you could try cleaning it with some carb cleaner and lint free cloth, replace and realign with VCDS, I tried this but it needed a replacement, the revision Q variants are the ones to go for.