how did it end for you?

something I can’t wrap my head around. one day everything is fine and we’re doing well/normal. staying with each other every night and continuing on with our normal routine. the next it’s over like it was nothing. out of nowhere and no explanation whatsoever. not even a conversation about it. next thing I know he completely blocks me out of his life and wants nothing to do with me. how can they switch up so fast with no feelings attached? not to mention move on to someone else just days or weeks later. probably had them lined up of course. I don’t understand any of it and it makes me so sad. I think it’s why I’m having the hardest time letting go, healing, and moving on with my life. I want to be happy and love myself even if I’m alone now but it’s just difficult. would love to hear from anyone who can relate