Thanks for your response. I changed the debug to true in the wp-config.php - gathering this is what you meant by changing to debug mode (I'm not a developer, I'm a visual artist who knows enough about dev that I built a custom site on WordPress, but I don't know much more).
So, what seems to have worked is that A) I found the pre-update NextGen version I had in an archive I'd saved of my entire site directory. I'm running 1.7.1. B) I did finally get it to work, though not perfectly, by just deleting the page and creating a brand new page for the content. I did have a default image set, I tried it both with and without a default image. The Facebook debugger was giving me errors about having both a default image set *and* having the meta tag of og:image checked. So I had to remove the default image in order to get Facebook to scrape my profile. And even with it set and "og"image" unchecked on the original page, it was still not displaying an image when posted on FB. Until I just deleted the page and created a new one.
So now it is working for my immediate purpose, but is still not displaying a text excerpt from my actual content - it's just displaying the text that is my general website description. This is ok for this particular page, but for a blog post I'd want it to display the text excerpt of the post itself.
This is the new page currently working only with the wrong text excerpt: http://ellendicola.com/Works/true-faith-2/
Here is a page just with video and no jpg image that is only displaying text (as I said no default image is set but this is because I was getting a ton of errors in FB when it was): http://ellendicola.com/Works/arborealis/
I can go ahead and reset the default image but aside from that there was something else going on, since I tried this many times to no avail yesterday.