Why do I feel like I don’t belong or deserve love anywhere?

My parents separated when I was little; my mother didn't look after us and didn't want to raise us, while our relatives always shunned and looked down on us. I spent my entire childhood being humiliated; I heard hurtful words for most of my life and never felt like a beautiful young girl.
I’m about to turn 21, and I don’t feel like I belong anywhere; I’ve never felt like I belonged anywhere in my life.
I am not at peace with myself; I do not love myself. I want to have a place in someone's life; I want to be loved, but that is impossible. Getting married is very difficult for me; but even if I did get married, how could I call my spouse "family"? I don't even know if they would want to be my family.
Why do I feel like I don’t belong or deserve love anywhere?
Post Opinion