I would personally play tighter pre at 2nl, something in the region of 18/15 and 3% 3bet. I should think that would make your new sizing much more profitable too.

I'd also be cbetting only for value or semi-bluff and sizing big for fat value. Sometimes you're going to get rivered, but playing elegant poker isn't the way to beat these stakes, as the majority of players don't really see things in terms of pot odds or implied odds.