Well first of all I really think that you need to be away from her for a while and work on getting back your self respect because if you don't then this relationship is just not going to work. But you can do it in a nice way, why don't you
send flowers to her to show that you are still interested in her and ask her to meet with you, then talk about what went wrong and maybe suggest to really take a break from each other and think about things because breaking up all the time is not healthy for either of you. Hope this helps!