Am I losing touch with a Champ That i Know and Love?

Ever since i've been trying new lanes I've been sucking at . It used to be were I was super good with him. Is it because I havent been playing top very much? Gnar got a 3 ad buff which shouldnt affect anything ive been used to playing. I've played Gnar nonstop since i got him in Late may/Early June with that Free champ promotion. I dont want to leave a champ that ive sunk effort into. should i go back to the basics and play gnar in draft mode till i get the hang of him again? any advice? [zombie-brand-mindblown]

note: to clarify things i havent been playing gnar where hes not supposed to be. just top.