I hope you don't cancel your therapy today. Your therapist is the best person to help you at this moment. He/she can help you rebuild your self-esteem and learn coping skills for dealing with your parents.

If you are feeling the urge to injure yourself lock anything you would use away or have someone else do it for you, from personal experince I know that it is easier to keep myself from cutting if I have nothing to do it with.

The idea of people in particular women being over weight drives me nuts, it was not until modern advertising that the super skinny look became acceptable. Before that time a skinny woman was considered unhealthy. Refute your parents idea of beauty and substitute it with someone else's. Google classical paintings and you will find a vastly different concept of beauty such as the Mona Lisa or hell any Caravaggio painting. Look at your neighbors I am willing to bet most if not all would never make it on the cover of any modeling magazine, yet them seem to find someone who loves them regardless. This is the concept to hold onto. No matter what someone will always find you attractive. I urge you to eat when you feel hungry not indulge your parents messed up idea of what you should look like.

I hope you feel better soon.

PS: If you and your therapist feel that you are both comfortable with it ask for a hug. Physical contact releases oxytocin which can help fight the onset of depression. In fact try to get at least 8 hugs through out the day.