How should i handle this?

Ok so basically me (boy/highschool junior) and my bestfriend (Girl/highschool freshman) (we used to do everything together and talk everynight all night, and she told me anything) got into a very nasty fight over facebook (cussing and all) sparked by her friend like 4 weeks ago, and ive tried to apologize but she said she didnt want to talk to me and told me to leave her alone. So its been a few weeks and she seemed like she was coming around but now shes totally ignoring me. I have tried a few times like twice since we fought to to talk to her over fb, or said a quick hi in person if we ped each other, but to her i could have been a wall. I know shes still mad at me and she has a new boyfriend, so I want to make it very sincere and I already tried in person yesterday but she told me coldly no in front of her friends and me, I want to tell her again but as I haven't cried in like 9 years she was the first person I cried over and I know if I make it sincere like I want to I'm going to break down in tears when I remember everything about her and June 8th is the last chance im gonna get so I'm shooting for that date and I want to keep it cool but so far everytime I think of her I'm on the verge of tears belivr me tried to move on but all 1000 songs on my iTunes remind me of her/I dream of her like everynight not intentionally I cant talk to my friends because they don't care, and I'm so regretful, but she won't even hear me out and has been nasty, and I know ur gonna say shes not a true friend but she was she used to care about me so much and she helped me with breakups and likewise and I always took her for granted... I'm always depressed and everytime I see her I know I will never have another friend like her... So today i tried to put her out of my mind... but i was sitting at lunch with my other bestfriends and my friend said he was going to confront some kid named (name) i asked who and was shocked to hear that it was in fact my ex-bestfriends boyfriend, so i pressed on and apparantly for the past year this kid has been writing hundreds of love letters to my friends girlfriend saying how he wishes they could be together and he is waiting for her to get out of her relationship with my friend, and that he would put any girl aside for her. This is still going on even though he is dating my ex bestfriend. This got me livid, because my ex best told me to go away because she loved this guy, but this guy is ready to cheat on her. Should i tell her about the letters? and talking to her over fb is not an option because her bf has access to her account, i cant really talk to her in person.... what should i do? its just not fair how hes filling her head with lies about me which im positive is going on, because i heard hes veryyyy immature