Bruce,
Sorry you were affected by this situation, but we had to remove support for Facebook from story maps in Sept 2016 due to technical reasons. The change did affect existing stories, and you can see a bit of additional information on our FAQ here.
Keep in mind that if you host photos on your own website it's best if you optimize the images for web display and create a thumbnail image. We've also got some information about managing images for Map Tours on our FAQ here.
Owen
Whoops! I totally forgot that Facebook support was dropped!
For utilizing your own site and making thumbnails, I recommend a program called IrfanView. It is free to use and makes it easy to run a batch process to make all of your photos into thumbnail sizes.
IrfanView - Official Homepage - one of the most popular viewers worldwide