Blog Photos From 2010-2013 Turned Into Spam?

The last time I posted on my blog was in October. I logged back in today to find that the photos in my posts from 2010-2013 now look like this:

When I go into the post and edit the photo, some of the actual photos are still there. I’ve had readers say they can’t repost my articles because social media thinks the posts are spam.

I use Akismet as a spam blocker and it’s been successful. What happened here?

Thanks for all your help in advance!