why being cheated hurts so much?
Because the person you thought you knew has become something that disappoints you - if you love them it hurts even more knowing that they could just throw away your love to do something with someone else. It's a horrible feeling and nobody deserves to be cheated on.
because, you feel like you have found the 1 and then relize that he is also wit another person and you care more about him when he just cares how many girls he can go out with and show his friends.
Because you trusted this person with all your heart that this person will never hurt you and will always be there for you. The betrayal of this trust is what makes it hurt most.
because its a betrayal. you realize that they dont care for you as much as you thought or would like them to have.