Filled with rage...what a situation again..

[Vanquish]

So i sit here now perplexed, on one hand i love my girlfriend. But on the other the girl she calls her best friend is talking **** about my financial situation behind my back, which i heard about through my girlfriend. My financial situation is not one that im particularily happy with, my fam is about borderline impovrished. My dads dying and needs a lung transplant and i work my balls off to take my gf out to dinner and treat her right because shes treated me like gold-better then any girl i've met yet let alone the 1 year we've been dating. Anyway thats alittle of my background on why im infuriated that my gf's best friend decides to rip on me about it due to the fact that me and the gf were scheduled to go to a party that conflicted with her best friends sister's party. This party that me and my gf were to attend i let her know before she even knew about her best friend's sisters party. Well this set my gf's best friend off and she said how my gf never spends time with her anymore blah blah blah and how im just using my gf for her money even when we have a compromising relationship and we share the costs of our dinners and days out because my gf understands my financial situation. After she told my gf my gf stood up for me and told me what she said..which is what set me off and its been building and building and to top it off my gf's birthday is on monday and im suppose to meet with her so called best friend who talks **** behind my back to help her decorate my gf's room. ANyway im so pissed that im shaking, how could my gf's best friend say such **** behind my back? jealousy? shes been in a bunch of relationships while my and my gf have been together and shes also contracted herpies and been kicked out of her house. So why does she take it out on me behind my back? I guess that wasn't all she said about me...but it irks me to no end and i wouldn't hesitate to tear her a new one in any situation i might see her in. What gives? She had no right to say that about me let alone to set me off now i have to deal with my gf's best friend hating me and me hating my gf's best friend but not saying anything yet and having the most amazing gf in the middle. Im so torn...