Sometimes when I think about her I realize that she's not the one for me.
Really? Could you explain what makes you feel this way?
It's because she's completely different than I imagined. She doesn't fit within my criteria.
If you don't like her then end it, it's okay to reject someone. If you force a relationship you'll just be wasting time.
I'm truly hurt that I got rejected and I feel like killing myself.
You can reject someone if you want or need to. There's nothing wrong with showing a little rejection every once in a while, and sometimes it is good to let people know your standards.