Disappearing blog images

I woke up this morning to find that almost all of my blog images had turned to this:

If anyone understands this, please fill me in! I did not change any settings or delete photos from any location. There weren't any copyright infringements.

Anyway, it was so awful to look at that I just went through and started deleting them. I'm working on replacing them, but for now lots of my posts will just seem awkward. Lots of pictures were linked to TPT or google drive, so I'll need to go back and fix all that. 

Thanks for your patience while I fix things!

If you have any advice about easy ways to back things up, please share!