Did I do the right thing with cheating girlfriend?

I broke up with my girlfriend because I thought she cheated on me....well a month later she started calling me and came out with that the night before I broke up with her she wentout for drinks with co-worker and stayed out all night (which this part I already knew)and said "He kissed me". I had asked her several times before if she cheated and said no I would never lie to you.it seemed to not bother her at all and did not even apology for ripping my heart out.....I treated her good....but being mad I told her she was a tramp, dont ever call me again and thank god i broke up with her....and I thought she was a piece of @#!&...well obviously she hung up...did I go too far...she started dating this coworker of hers the day after we broke up....she was also very inseure in our relationship and constantly accusing me of cheating....even ccusing me while she was actually cheating on me crazy huh?