I Was Hurt By Someone Who Doesn't Care That They Hurt Me

I met a guy on a site called Locanto. I fell in love with him but I found out soon enough that he was a player. The breakup left me devastated and I wanted to remain friends.
I had no one to vent to in real life. I befriended another guy on locanto and told him about my breakup and shared everything. Little did I know that this man would text my ex on locanto.
My ex confronted me in person and I felt guilty. What he thinks is betraying of his confidence was me actually venting to a third person because I was so damn hurt and losing my head.
I met him and hugged him and tried to explain as best as I could. He used the situation to get into my pants and get physical with me.
I don’t know why I should even feel guilty because he never felt guilty about cheating and lying to me etc. read my earlier stories please to get the complete picture