Issue 1: File path error
I’m not sure why the file path is erroneous, but I replaced the file paths in your pastebin with the image sources in your website, and it worked fine. If you’re still having issues, try hosting your image on a media management service like Cloudinary and using that link as the source to see if you’re still having issues?
Issue 2: Incorrect dimensions
The first thing that struck me is that because there’s the “post__image post__image–full” classes, the width and height you set for the image are ignored. Instead, the full image CSS class sets the image to the full width of the page.
To fix this, set your image class to “None” in the Insert/Edit Image dialog and ensure that the dimension are correct. I think “Centered Image” should work as well.
Double-check the Source code to make sure your usemap attribute is still there.