I cant even set a new frame without it snapping back to the first one. Just yesterday I managed to animate a camera and now I cant even animate a piece of glass rotating.
can you disable the proportionel editing,
just a guess!
You probably have keyframes. After animating, register a new keyframe for any animated property, sometime before changing frame or saving/quitting or rendering.
Yes, the problem is almost-certainly going to turn out to be keyframes. Or possibly drivers, but unlikely. There is something that is right now calculating the “next position” of this object when the frame-number changes. Look at the Curves Editor, Actions, and so on.