what do i do

so (backstory) me and (s) have been friends since we were fetuses , literally . atleast 8 years , shes been my closest friend forever & we bond so good . but one thing ab her is she is a "snitch" ever since we've been friends , she would tell my parents everything i did , after a few years she grew up & stopped doing that . this year, i have a bf for over a year now and he literally means the world to me , i never wanted her to know his snap or number or even know he existed cus i was afraid she would do something to ruin our relationship . she ended up finding his snap and thats exactly what she did . she told him about a bunch of stuff i was doing (suckin dick & fuc*ing people) which isnt even true . me and my bf fell off for a while and i hurt so bad for so long.. literally the type of hurt where your not asking for things to go your way, your just asking for it to get better, you know ? we ended up getting back together but he doesnt trust me and he is alot different now . he's really nonchalant and he even said "its diff now because i kind of expect you to do stuff" (talking about cheating and or lying to him) of cource i feel like i shouldnt stress over this because i didnt even do anything wrong! but at the same time i love him so much im willing to bite my tongue and just work on him trusting me . ever since this went down, i have refused to talk to (s) or acknowledge her . but lately i have began to miss her so much , we had the best times together & ever since me and her stopped being friends i havent been having any fun or doing anything outside of school . im positive she would do this all over again if she had the chance and i feel like i would look extremely stupid ever being her friend again ! but i miss her so much ive considered dropping all of it . she caused alot of hurt for me , ad she acted like it was not her fault & that she did nothing wrong . i feel like since me and my bf are straight, it wouldnt be so bad to just be her friend, but then again what she did was awful & idk how to get over it . i dont know what to do..