Eat ice cream. This is not a joke. The best advice I can give you right now is to eat some ice cream (in moderation).
Without any context, we do not even know 'what' happened. Did they die? Did you have a falling out? Was it their fault? Was is yours? Did they reveal that they are homosexual, but you are a homophobe because your parents filling you with effed up "values" from the bronze age?
I respect your privacy and you probably had good reasons to not share the details, but this is something you should talk about with your 'other' friends. Not with a bunch of strangers from the internet.
TigerPlushiefire
i should say go their family and friends for support. or try to remember the good times with your best friend. thats all i got say to help you, please dont thank me I was never here