Been there done that. I can also be a real jerk if I want to but everytime I see that smile and hear that cute voice I can't help but loose my "bad boy" demeanor. It hurts, yes, especially when you are so madly in love with that person but all she could do is go yap..yap..yap..yap about her boyfriend. You want to be indifferent to her, even rude at times, why? Because you are tired of hearing about that jerk and his antics, because the mental agony you suffer from it exceeds any physical pain that you may have endured in your life. You are tired of being just a friend, you want something more from her to the extent that you start devising plans to ruin her relationship. But then you hear that angel voice in your head, "Why would you wanna do that to the love of your life, is this really how you want to win her heart?". Now you feel disgusted with yourself to even have thought about such a plan. Love is all about sacrifice they say and sacrifices you have made. You can't take it anymore, you want to end it all, but then you remind yourself, "Hey atleast, I am lucky enough to be with the person that I love". Yes, you want to hold her hands in public, you want to shut her up and just kiss her when she is acting all cute, you want her to hug and kiss you when you are feeling down, you want to sleep with her and wake up with her and pamper her by making her breakfast and you want to be recognized as the man in her life. But hey, remember when you read that love is all about sacrifices, well these are just the sacrifices you have to make to be with her. Its not exactly what you want, but its atleast better than nothing.
A great man once said, "Its better to have loved and lost than to have never loved at all". Its true in your case, and you better be thankful about it.