how to get over being upset?

a while ago my best friend posted on my face book account " ur not korean or ******* jap , ur thai so learn to be thai know ur root and stop being a pretender " it upset me very much and i can't get over it, here is the story

he particpated in becoming a monk and i he was on face book everyday , though im from thailand but im not budhish so i said " aren't u suppose to pray and not get on internet ? , i know that ur suppose to participate in the realm world and leave entertainment alone ? " then that's what i got from him, many people told me to forget it because it could be jealousy because i speak korean,japan,eng,thai and greek but i was hurt and now i am not forgiving him " i know im being childish " but i thought that even if i was what he said i was why would he wants me to change let alone post it on my facebook so all my friends can see it , ******* asshole , its been over a year and i still can't make peace with it , i now hate that miserable loser who lie to everyone he's a cop but only a security guard , got a girl pregnant then had to live with her because of his kid , then to top it off he came from a poor family that his mom had to divorce his dad so she could marry a white guy to give him american citizen, im just green card but on the other hand living my life , i travel a lot and my family own our own business but he just had to ruin it by saying those thing , i nver once mention bad thing about him but now i will - ******* loser! ahh sorry =( i am very proud of who i am that's y i am so pissed off