I'm looking at Gerry T's list from the Invitational right now and the scariest things I see are 2x Golgari Charm. Their answers are all generally more expensive than our threats. And their clock is slow enough that we have an opportunity to recover from discard.
I'd probably just bring in Abrupt Decays and Scooze #2 (I have 1 main). You may have just been getting god-handed by them. Do you have any specific play-by-plays you can share? That might help us see where you are having problems.
Edit - unrelated, but I was messing with a Modern deck and saw a card that could be interesting to use -
Defense Grid. Is there any merit to this card? Or am I trying to be too cute?