Most Helpful Girl
Take this hurt and turn it into action.
Block him, his girlfriend, or whoever he cheated with, just move yourself away from the things that remind you of him or the hurt he caused you.
Now, instead focus on you. Go on a mini adventure/ like get a camera and just explore or something/ something like that.
Don't be on the bed, crying for hours; don't day dream or make up scenarios in your head.
Don't stay in the shower only so you can ponder on it more.