regression again to another world

My name is Sid, I was just a 17 year old boy in on earth until one day, I was unfortunately killed in a freak accident and died.And I found myself in a new world tasked with killing the demon lord you get it a normal isakai fantasy world... but how ridiculously wrong I was. I slayed the demon lord and brought peace back to the world. Unfortunately, my happiness was short lived as I soon found the people of this world fearing my power and not long after I was given the death penalty for false accusations. And to my astonishment I was back on earth with my magic power intact and in my old body.How would I face earth again? But then my mind drifted to my old school bullys but things would be different because with my past experience this would feel like a walk in the park.