Will he fancy me?

So after a breakup I gained quite a lot of weight. I've found it really difficult to shift it again and I'm soo self conscious. Stretch marks have appeared all over my body and I used to be so toned and slender and now I feel like a jiggly mess. A boy I've been texting but have never actually met has asked me on a date next Saturday and he's never seen my body. I'm soo nervous that he will find me too fat and not attractive. I'm terrified of him rejecting me and the feeling of humiliation. I almost feel like he's dating me as a joke because he is soo gorgeous and handsome and smart I'm wondering why would he ever want me?