Rate on a scale of 1 to 10 how bad i screwed up +advice

Well it all started with a girl, or course. I was young and looking for love and I found someone who was cute caring fun loving and all that. I was happy, very happy. Apperently she wasnt. I guess I sorta messed things up when I said if you dont love me...

for me then leave...cause she did, but I realize now that I want to change for her, because who I am is not a good boyfriend, I complain if I dont get what I want, I constantly ask her for sexual stuff like pictures or sex even when there are people around, the other night I bit her head off and yelled at her, I feel so bad about it. I love her and ide do anything for her. She is my life and my world without her I am not me. Shes going out with another guy 2 days after we broke up, now I feel as ill never get her back... I cant bare that. So on a scale of 1-10 how bad and also could someone give me some advice on how to show her that I love her and are willing to change?

you were about a 7. but if you truely love her. then you need to start changing. you need to tell her that you love her and she needs to see that you are trying to change

I cant show her that if shes not with me, and I wrote her this the other day

love
I love you
more than anything
and I would never do anything ever to hurt you conciously
if I am ever hurting you tell me because ide rather take my life than to hurt you
this feeling that I feel when you remind me of how bad I treated you kills me, makes me want to die
your the only thing that keeps me alive with the happiness you bring
you are my life, I would never hurt my life
I promise to care and love for you with all my heart and soul
I will never force you to do anything that you dont want to do but I pray that you can think about how I feel sometimes
I need you you are my will to survive
but if you only decide to go out with me because of this last line then disregard the last line
I cant say much more than I love you

Don't feel bad. No one is perfect. Whether you get her back or not, at least you learned something from the relationship. Your heart is broken, but it'll heal. Don't write her or talk to her anymore. You told her how you feel, the ball is in her court. Give it some time. If she realizes she wants you back, she'll let you know. In the mean time, concentrate on getting over her.