Can't learn new champs

Hi guys. I am an OTP kayn or at least I was. now I can't really play him quite good and I can't learn other junglers. i tried zac, graves, and kha'zix ( who I mained back in s6) but now I can't do any thing and I can't carry my games and my safe picks are my feeding picks. I thought of becoming a mid laner but my picks in mid are yasuo and zed and we both know that they are usauly the feeding champs in mid and the most hated and banned why is league so hard now? why can't I learn anything new? (also I tried to main top and me kind of became an otp with kled on top but iam not entirely good with him ) ... so what do you guys think ? should I change my role ? should I change my picks ? or should I play what I like and not give a damn about the rank and other players etc.