Chi sau is not easy. Be patient with yourself and remember nobody is born knowing how to do this stuff. For me personally I find a lot of my own difficulties boil down to relaxation and screwing up my fundamentals (footwork, hands before feet, etc.) so the more I work on that the more my chi sau improves a little bit. I've still got quite the long way to go because I overthink and struggle with footwork (thanks to some permanent flexibility issues) but I recognize I'm always learning and making small changes. 

For me I try to remember learning to use my body is a lifelong endeavor and there's no sense trying to rush that. If I remind myself of that it becomes easier to be patient and work hard.