Just block 'em. They won't bother you anymore. And about your best friend - I'm sorry to hear that. I'm not good with words, sorry. There must be some reason as to why your best friend wants to leave, right? Maybe talk things through with them and tell them how much they mean to you and that you don't want them to leave. I don't really know your situation, but I don't want to inquire if you're not comfortable with that. Just, take care of yourself, ok?