Lupita,
I wonder if you could look at this as, not something that happened to you, but rather something (or someone,actually) that you embraced with your whole heart and then chose to separate from because he wasnt good for you. It is still painful, and of course you are crying tonight. You shared some very intimate moments and that cant be done without having your heart hurt when it is over.
But, in all of this, I see you as less of a victim as I do a strong woman who chose a man and then realized that he wasnt a good choice for you. And then you acted on that realization. You did what was best for both of you.
I dont know for sure, but if your friend was dancing cheek-to-cheek simply because that's the way the dance is done, then she may feel offended that you are seeing a betrayal in that. That may be why she wants an apology. She may (and I dont know, I am just guessing) not be the kind of person who tries to steal boyfriends and it may be upsetting to her for you to think so. That may be what is at the root of the demand for an apology. You will have to decide what you can do about that.
I think it is very insightful for you to continue to tie your feelings about your boyfriends behavior to your feelings about your mother's behavior. When you have gotten through the fresh grief of this loss, I hope you will examine the connection between the two. I think that some of your feelings of victimization may be tied to your relationship with your mother--where you truly were a victim. In the relationship you just ended, do remember that it is not the fact that you were not able to change his mind that made you a victim. If you had not expressed your feelings, or if you had not been honest with yourself that this was not workable, or if he in some way deceived you about his actions--those might have cast you in the position of victim.
Dear Lupita, be gentle with yourself while you mourn.
CB