This is written in "your" perspective, italicized parts are flashbacks. 

He’d be better off without me, happier and with fewer worries. Someone as broken as me doesn’t deserve a guy as talented and amazing as he is.  

“I’m breaking up with you”

The pained expression on his face broke my heart into a thousand pieces. If only he knew how much it hurt me to say those five words. I let go of the greatest thing that has ever happened to me because I knew it was for the best. I love him enough to be the first one to let go, it was bound to happen anyways.  I’d rather have him hate and forget me than for him to worry about someone as worthless as me.

“What? Why? Did I do something wrong? Is it because I’ve been busy? I’m sorry, we’re finally making a name for Infinite and I know I haven’t been spending that much time with you but I promise the moment that I get a break I’ll spend it with you. I don’t want us to end, ever.”

His eyes began to brim with tears, and I was fighting to hold mine back. I was so close to telling him how much I love him but I couldn’t do that. This is for his own good; a girl like me would only hold him back.

"I can't be with a guy who sings and dances in front of teenage girls for a living. It's too difficult. Just leave me alone if you want me to happy. It's over."

“…I-I...I never knew that being with me made you so unhappy. I... I’m sorry.”  He looked so torn… His face was buried in his hands when I turned around for once last looking before walking away from the best thing that ever happened to me. I knew he’d let me go if it involved my happiness… even though I was lying.