Culturally Speaking: People make mistakes, but it doesn't matter?

Hm. I have a domestic battery conviction for getting into a fight with my ex-girlfriend from 3 and a half years ago. I served 13 months for it. I am applying for SSI now, due to my inability to find employment. I was working a decent job as a claims yst beforehand. So much for "the past being the past" huh? Should I begin judging everyone by their past now, also? Mind you, she hit me first, I retaliated in a fit of rage. I am not a violent person, by no means, and this is my only criminal conviction in my entire life. This is an isolated incident. Guess it's something I'll have to accept, huh? I guess people don't or cannot change, or be forgiven for mistakes. Employers seem very reluctant to hire someone with a criminal record, especially a record for a violent crime. In all honesty, there's nothing I need to change. This was an isolated incident. I am not a violent person or a criminal. In actuality, this 13 month stint feels more like a life term.