LOLOL. Man I gotta laugh because that has happened to me so many times. First I have to say that I don't know the answer to your question, but I do have a fix so that it never happens again. When you begin a new project and before you have done anything, create a new camera by clicking the camera button. Then select that camera (usually camera2) and work from there. Create additional cameras as you work but NEVER touch camera 1. Always let that remain your default camera. I am sorry I couldnt help you out immediately, but I think my tip will help you out in the long run.