While I think it is possible to hallucinate under extreme amounts of stress and anxiety, you might want to get this checked out just in case. You are aware it isn't real though, so you can rest easy knowing you haven't lost your mind and aren't losing it. However, even though it might sound cliche, no one on here can tell for certain what is exactly going on nor diagnose you. It would be good to get a psychiatrist's/psycholigist's opinion just to be sure.