Getting destroyed on my main

I am a silver 3 ryze main and i have been playing the game for almost a year. Today i was playing my promos and i was against fizz who completely destroyed me in lane and made me useless the entire game. So after that game i was wondering if i get destroyed on my best champ what is the real problem? Is it my mechanics, my build or the champ i was playing. Also i need tips to play against fizz i don't want to keep banning him forever.