Wind buffeting with batwing fairing on honda shadow 750 Spirit (2012)

I got a memphis shades batwing fairing with a 9" windscreen for my bike, it looks damn cool and protects my body from the wind, but wind buffeting turned my helmet into a vibrating sex toy above 50 mph.

So, I got memphis shades lowers. They helped a tad, but did very little -- I was able to get up to 60 mph without tons of buffeting, but it came on strong after that.

My question is: what should I do to correct this? Should I go for a different windshield? (that would suck,as this whole setup has costed me about $600 and I can't return it at this point -- also, this setup looks cool). Does anyone else have a similar bike? How did they manage the wind with it?

I'm kind of wishing I just went with a smaller screen to keep a little wind off the chest.