I'm so sorry you are going through this, Ambra.
You are not disgusting. An ED is an illness which you are trying to deal with. You are doing something really difficult and painful. How dare they judge you at your GP's office!

I think you should contact your T again and ask to get your session back. Ask if she can maybe see you sooner than Friday. She is there to help you through this, and I'm willing to bet she's had clients cancel before and then retract the cancellation. (I've seen lots of people writing that they have done that, here on the boards, so it seems like a pretty normal reaction for those who struggle with feelings of shame.)

If your T wanted to work with only shiny happy people who were uncomplicated and healthy, she would have chosen a different profession. Please let her help you through this. We're here for you too, of course, but you need your T's help, too.