Honestly, just move forward and show that you're a different person than you were back then. People make mistakes, screw up, have bad moments, it happens, and I see it all the time. But if you show different behavior, show that you want to play on the server and aren't toxic and are generally someone that other people want to be around, your reputation will change. It's not going to happen overnight, and some people may still hold that image of you forever, but that's pretty much the only way forward.