It's unbelievable to be in this position where I suddenly hate my girlfriend
Well it does sound like a sudden change. Why do you now hate your girlfriend?
She had sex with passive objects without me.
If you are unhappy in your current relationship then you should break up with your girlfriend. It is wrong to hate anyone and you need to work on accepting your girlfriend for who she is.
I think I just can't get passed her selfish personality and the passive object thing.
If her personality is a problem for you, then it really is time to consider breaking up. It'll will be good for both of you to move on and find better matches for yourselves.