Boyfriends female friends (VERY LONG)

With my boyfriends female friend. She, for two months, consistently kept talking to him about how horny she was, her sexual life, her personal life, and relied on him for emotional support. At one point he was so overwhelmed by her issues that he could no longer put effort into our relationship. (That was the lowest point) 
Since then, things have gotten better, but every small thing be does for her (Getting off the phone with me to call her for a few mins, listening to her problems and offering advice via text whilst also talking to me, generally mentioning her in simple conversation) gets me so so very bitter and angry. He abandoned me emotionally for her and since then has made me feel second best in my own relationship. 
I did confront her about the sexual nature of their conversations, and she did agree to stop that. But that didn't stop be from feeling agitated and upset when he would bring her into everyday conversation.
There was someone else who also ground my gears in the same way, but i reconciled my differences with her, since their relationship was very platonic and honesly she is a sweetheart anyway and i was only against her because of this expeience with friend number 1 here. (See? I did do my best to get past my issue, but i really  couldnt let it go with the first girl)
Aaanyway, since then, we have had fight after fight over this girl and the way he makes me feel unimportant. Finally, he just now texted her saying he did not want to be friends anymore.
I feel so relieved and giddy about it, but honestly i do have a twinge of guilt. Should I be feeling bad?