Every time I leave my scene, everything in it gets deleted

I made a project and had been working on it for a while. Everything was working with the scenes I made at the start but for some reason my new scenes just stopped working. whenever I leave a scene that I made today everything in it gets deleted including the directional light and camera. I have made sure to save them many times but it still deletes everything I do. when I go into my files they say that the scene takes up more space than an empty scene should but everything is gone.