How did this happen to me?

I saw you in the hallway, you smiled
I messaged you, you were happy to respond.
I said you're cute, you said you're beautiful.
I said I like you, you said I love you.
You promised, forever.
I believed you.
You found someone else.
I saw you in the hallway, you looked away.
I messaged you, you never replied.
I said you're cute, you said your girlfriend told you the same thing.
I said I like you, you said you didn't anymore.
I asked what happened to forever, you said it doesn't exist.
Now I sit on the bathroom floor. Surrounded with drops of my blood.
I looked at the cuts, beginning to heal.
It didn't hurt as much as my heart.
Pushing my blood through my veins, until it leaks out through the open cuts.
How did this happen to me?
It was that boy.
The only person who could take half of me away simply by walking away.