Mentally stressed

I keep looking at photos of thin, pretty women and wishing I could look like them. I want to be thin and pretty, or at least thought of as kinda sexy. I wish I had someone to hold me and cuddle with me, but I'm having no luck. I'm depressed and lonely. My sister is coming up town and I haven't seen her for a couple years. I have lost a considerable amount of weight since I saw her last, but I am not where I wish I was. I need to lose more weight. I am not thin enough or pretty enough. I am so upset with myself right now. I feel fat and ugly, homely and alone. What is wrong with me?