Hi there, @Erik_Smith
I am really sorry about this inconvenience!
If you face this issue again, please let us know, and we’ll gladly remove it from your feed, so you wouldn’t to create a new widget for this.
We also agree that it would be awesome to automatically remove deleted posts from the widget, and this idea is already on the Wishlist. Feel free to upvote it here 
- Remove deleted post from the feed automatically