Define what +ev means to you in cash games.. sounds like a SNG/MTT term to me.

In other words, make sure you are getting the fundamentals right in cash games. Build big pots with a lot of equity, pot control marginal hands, raise/reraise until all in with your strongest hands etc etc etc

Downswings have little to do with a cold run of cards and more to do with little mistakes you are making along the way that really add up.

Keep plugging away and learn to make less mistakes= less variance.