I have a friend with a fear of leaving her house because she has the same issues. She thinks people are looking at her, watching her, laughing at her. She is self conscious about her body and her appearance. The truth is there's nothing wrong with her body or appearance. There's nothing wrong with anybody's body or appearance. There are all different kinds of bodies and we all look different.
It's unfortunate that a lot of Western popular culture supports looksism, and sizeism, and all different kinds of things. But you don't have to let that shape your life. I'm not saying 'Don't feel the way you do' or 'Just get over it'. Not at all. I too have a hard time leaving the house a lot and I feel like people are always looking at me. Sometimes they are. I've had people say **** in the streets to me about how fat I am, laugh and point, etc. People are ignorant.
But you don't have to let it run your life. You have every right to be out there, just as much as anyone else.