I feel like I am ALWAYS being watched. Have any of you ever felt this way? How can I cure it?

I feel as though I am constantly being watched, and it's driving me crazy. I feel horribly embarrassed when I shower or use the washroom. This feeling also prevents me from doing things that I want to do because I feel like people are watching me and will judge me. If you can't find an answer to this, then could you maybe tell me that people are not watching me, I need convincing. Thanks guys.