Dude, I feel your pain. There definatly seems to be a big difference at play at these two levels. I played the same style at both and look at these graphs.

NL100

mmmn nice smoth profit

NL200

WTF??

The only thing I can think of for this varience is that players tend to be more aggressive at NL200. Unfortunatly theres not much you can do to counter that as players are often more aware of pure nut peddling.

Putting more effort and trust in reads helps a bit but try changing sites, I've play semi TAG and have had more success on passive sites like the ones on the iPoker network (no Pokertracker support but maybe thats a good thing). Also a good rakeback deal will pay more at this level and go some way to easing the pain.

Don't give up though, playing against good players, although expensive in the short term, is the best way of improving your own game. Think of it as tuition fees