I've been ghosted by someone who was friends with me for 5 years, I get the feeling, you ask yourself what you did wrong and if there's something wrong with you. Sometimes it may be your fault and you'll never know it, or sometimes people just stop caring, tormenting yourself about why they left will only make you crave this non-existent closure. If you need someone to talk to I'm happy to listen, I know the feeling all too well.