being alone

my mom did told me once that sometimes the person that you really love alot, you have to let it go. but what if my mind say that i can change it and make it last till i die? i started to fall bits by bits into the drain and get drown. am i making the world most biggest mistake ever, of letting him go and never to return again? i know i've been being so ego and selfish, perhaps that is my mistake and am i feeling regret about it? i dont know. im puzzled and having a break down. dear god, please help me to stand up back and go to the correct path back. amin.