I've prepared a small hint, just in case you encounter a bug.
!SPOILER!
After hiding in the toilet, you'll hear knocking at the door and will have few conversations through the wall with the imposter, then you will have some additional time to figure out how to survive until he beats down the door.
When you closed the door, two clickable objects were activated in the toilet, so you can click on them now to figure out how to survive. If you encounter the imposter going through the door immediately after you hide, or have issues with other objects, please notify me. A message will be enough, but a screenshot would be helpful, or ideally, a video.
Hopefully, this time it will work out! Good luck with beating the game!