So is fizz unbalanced?

I honestly want to know if I am good with him or if it's mainly the champion doing the work. So the basis behind this post is because I just bought fizz and then played him for the first time, I had to look up a build but I carried so hard that i was wiping out over half the enemy team by myself and I made most of the enemy salty as hell by the end of the game. Second game came around and even after multiple missplays in mid and a few deaths early on I still ended up carrying as well. For a reference point all of these guys were high gold and low plat so they weren't stupid nor do think they've never played against a fizz before. l'd like to point out as well that even though it was my first time playing him I constantly watch pro's play him and have a full understanding of his kit + I learned all of his combos and when and when not to use abilities properly.