Pinky promises (BTS X Reader)

My name is Addie. When I was nine, I pinky swore to my father that I wouldn't fail a single test again. After I started getting good grades, my friends started calling me a nerd and I started getting bullied. Only one of them stayed by my side. I promised her that I would go to her volleyball game and I missed it. She left me after that. I started feeling like I was drowning back then and since then, I decided not to make promises again...because every time I promise something, my life changes...till this moment.

"Let's do this," he said after kneeling in front of me while clearing away the tears from my eyes "whenever you can't love yourself and you are like this, I will love you on your behalf, I will see in you what you can't. And whenever I lose sight of myself, then you will love me on my behalf and bring me back"

His mouth was smiling but his eyes were dead serious. I could feel the tears accumulating again in my eyes. I wept them off with my sleeve as he grabbed my other hand. The first thing I saw was his pinky intertwined with mine "Pinky promise? ...We need a seal" It was like my body was moving on its own and I was just a spectator...My thumb was pressing his and then he hit me in my forehead bringing me back to my senses "Sent! Now you can't back down"

Again another innocent promise with good intentions that eventually turned my life upside down...Why are promises so painful?