My bst frn cheatd on me n now i cnt get bck the trust!?

a girl ws my bst frnd 4m my young age... we nvr reli had any big probs in our friendship! but a few yrs ago she bitchd bout me to hr bst frn(whu wsnt close to me) n then v stopdd tlkin 4 6mnths.. bt latr v strtd tlkin! nw t has been 3 yrs.. bt stil i cnt 4get the past i cnt trust lik b4! i cant tel her al stufs bt. i did nt tel her tat i had a boyfrn n nw she found out n so she is nt tlkin wit me lik b4! wt shld i do now?? she dse nt knw tat i dnt tel hr stuffs cus of this mttr.... she tinks t s us i dnt tret hr lik a frnd! bt the truth s shr reeli means a lot to me!