why can't I be perfect like my sisters?

Why can't I be perfect and pretty  like my sisters? No one looks at me the way they look at them... I have always been kind of an outcast, even in high school. I was the girl no one talked to, I went to dances by myself.. Right after graduation I started dating a guy I went to school with. We would have been together 5 years this sweetest day however he left me for my best friend.. It's been 6 months since we split and he's tried to take my son from me and tells me how worthless I am daily. Now he claims he wants to work things out and be a family, though when we are supposed to go out he only ever takes me to his house sleeps with me and then makes me clean hi house.. I'm starting feel stupid.  He always points out how cute or sexy he thinks other girls are.... I don't have  a perfect body  or a natural complection. I also have many allergies asthma and eczema but do these make me less of a person? Do I move on or try and tough it out  ??