boys :(

so like I’ve been having a crush on this boy for a while now & I told my best friend. my best friend is so beautiful & well she told me he was cute & that she had him in a class & that he was trying to talk to her. she knew I had a crush on him & lead him on to liking her more & more until she finally told him she didn’t like him. he’s pretty hung up on her & they are always talking. she told me the other day (knowing I still have a crush on him) that they promised to be each other’s prom dates if they didn’t find somebody to go with. I feel kind of upset & betrayed :/ any advice?