what evidence I need to prove that I wa discriminated by my Supervisor.

I was treated unfairly by my Supervisor for a long time, he embarassed me, he yeld at me, he accused of lying and he's being very rude to me. my co-workers come in late, leave early he doesn't care whether they gave a leave slip or not, they getwhat they want they get to work where they want and they get to take off very often and me if i was late even just 5 minutes he will asked me for a fifteen minute sleep and when I asked for day off, he will procastinate or he will give me the run around before he approved it. I have a previous EEO settlement in 2008, but most of the condition on that cotract were violated can I still enforced that contract even it's an old one? My supervisor retaliates and discriminate me and recently I was demoted even though i was doing my job.