It may be a clogged fuel filter or fuel line. I had that problem recently in my Turbo S, and that is what the problem was.
I was able to fix the problem with two cans of fuel line cleaner, but I cannot remember the name. (It had a "40" in the name, and I got it at the VW service). It was rather expensive, $20 per treatment, but still way less than the dealer fixing the problem.
It also me be the fuel pump, a worse problem. I would start with the fuel filter, and some kind of "Gumout" type treatment.
Next, always use "quality" gasoline. Never conveinence store or grocery store cheap gas, and not Arco or Texaco. Use Chevron, Union 76, or Shell. Yes, there is a difference, and always use Premium. Our TS's need that.
Good luck to you, and welcome!