I wish I wasn't so sick of my girlfriend. She's so damn gorgeous.
That sounds selfish. Why are you sick of your girlfriend?
I'm just tired of her.
It sounds like you are only staying with your girlfriend because of her physical looks. That's a very shallow reason to stay in a relationship and not fair to her. If you really are tired of being with her, you should break up so you both can move on.
I don't know if I want to break up.
Everyone has doubts from time to time when they are in a relationship. Relationships are difficult and require hard work to maintain. Talking to your girlfriend about any issues might help you make up your mind about what you want to do.