Would you say I over reacted with this....I mean I guess I do sound kinda crazy...?

[sammy J]

My boyfriend doesnt exactly have a clean backround, this is his 4th chance actually and it really seemed like he changed. I was on his Twitter today and he was talkin to like 4 girls, about games and PS3's or whatever but there was a hint of flirting in their conversations which angered me. But what angered me the most was a conversation he had with some girl about her breasts basically. He asked to borrow her top, she said he wouldnt be able to fill it out, he said he'd get watermelons. So in my anger and in the spur of the moment I commented on this conversation saying something along the lines of fuck off you slut lol, I text him too and was raging at him. Anywo she replied "He's my cousin you sicko" ??? I was like wtf? So I said "what kind of creepy ass conversation is that to have with a relative, your the sick one!" and then she called me a "wee insecure fuck"....then she rang my boyfriend yelling down the phone to leave me cause Im a crazy physco bitch apparently. So anywho, im sitting here crying, thinking do I break up with him or not, I love him so its not easy and now my mind is mush and im so confused and angry at him and her and myself.
any advice? Have I over reacted?