Am i being too bitter? need an opinion?

alrighty then, this thing keeps draging along, long story shorter...one of my best friends starts ignoring me for stupid reasons, then she comes back and appologizes, apology accepted....then she starts thinking im doing stuff on purpose to get her back for what she did, then she says she doesnt need me or anyone....she literally has 3 friends and its alittle heart wrenching cuz we've been through soo much the past 5 years, she over reacts to me being slightly late to something we had planned, and we go back and forth, until i said that whenever she gets over whats she is getting over to let me know, cuz all i heard that day was how i was a jerk and a douche for being a little late to play tennis one morning, where she had plenty of time to do anything, no plans at all.....so dont ask cuz she was busy CUZ she isnt....i feel like ive been down this same damm road with this chick, and oh im a guy so ive been through even more hell ....so now i have the sudden urge to break character and just say screw IT!! cuz i really am up to here with this girl and her ivory tower monologues, goodness i feel like pure bitterness, and hint of sadness looking back at what we've done...but my anger over powers everything, it will take all the strength in my body to not get pissed the next time we talk, even if she apologizes again....its almost not even enough...this $hit is about to get real LOL.... so what am i being stupid in this situation?