Have you checked nothing went down your turbo pipe? Bit of a pita to get the clamp off. A torch and some long thin tongs might be handy.
VCDS scan whilst running to 5k should show if you have a timing, misfire, fuel pump, etc. matter.
My old stage 2 map would feel like it was pulling back around 5k, changed maps and it was all good.
Hope you get to the bottom of it at Awesome.