I think this poem is a great way to express your feelings and emotions.
It must have been difficult to try and get your friend to forgive you. It must have been difficult for her too.
My honest opinion is I very much dislike the idea of cheating and it would be heartbreaking if it was one of my friends that did it to me. What I like about your poem is the honesty in it and that you realise that you hurt your friend.
I love the rhyming in this - it was an easy poem to read and full of emotion.