Struggling with Body Image and Self-Love

I feel sick all the time. I look at food and add up all the calories in my head to see how much I can have. I feel like every time I eat I need to run to the bathroom to get rid of it as soon as possible. I never do. I can't bring myself to. I know in my head food is good for me, I know that it's energy for my body. I know this. But why can't I loose weight? I have always been over weight, ever since I was a child I've been over weight. People look at me and assume I am eating unhealthy. My doctor even wrote in one of his notes "obesity due to excessive calories" I don't eat! Yet it's always presumed that I do. The worst part is, is that I know no one will ever be good enough for anyone's particular standards. You can't accomplish that, it's impossible. You might find people who love you for you, but every one is not going to love you. So why care what people think? Why not be happy in your own skin? Why not love yourself? And what makes this hard is the fact that I know this, I preach this. Yet when the day is done I look in the mirror and asks, "why am I not good enough?" "will I ever be good enough?" "will people love me if I'm skinny?" "will I love myself if I'm skinny?"