If you're unable to find your post in a specific room, we may have moved it to a different room. If you click a link to your post and you see the message “this post has been removed” it means that either your post has been deleted, or, sometimes, it means that your internet connection was interrupted just as it tried to load the post. You can check this by checking your internet connection and exiting the app before tryinga again.
You can always find your posts by navigating to your Community Profile. Just click on your profile picture (in the upper-left hand corner of the Community page) and scroll down.