Fixing a tarnished reputation?

after years of working at the same company people grew to like me and i liked them too. in the last year i was introduced to a drug called cocaine and was addicted for 2 years. i ended up becoming an asshole and non of my colleagues want to even look at me anymore. the girls like i just want to have sex with them and the guys dont talk to me either. i dont know what to do right now. i stopped doing drugs for 2 years now but just realized how bad ive been acting these past few months. what should i do to show everyone i wont abuse there trust anymore and that i am back to the same guy i was before?