Broken Media Images and Image Linking Issues

Good morning/day,

I will try and be as descriptive as possible so that you can understand my issues that have recently occurred in my WP admin area.

Have a few items that I am sure are related to each other. I am not a huge tech person, so hopefully the directions for fixes can be provided in easy to follow steps.
I am running WordPress 4.2.2 running classifiedstheme theme. https://www.panamaenglishserviceproviders.com

Issue #1: About 1.5 weeks ago I was previewing other themes to use (never activated any of the themes, just using the preview function). That is when I noticed an issue in my Media Library. Nearly all the images in the Media library are showing as broken…(about 95% are showing as broken) Some images I can click on and view, and some can even display in the media editor… some don’t do anything at all. But images are all appearing fine on the website and working 100% as far as I can tell.

Issue #2: When adding new images into the Media Library appears fine, however when I try to add a new image into a classified listing, I get strange message in the listing image url field saying ‘undefined,’. I have to manually load the image into the media library, then copy the image url and paste it into the classified listing image url field…

Issue #3: I discovered this the other day, probably related to these issues. Found the image links in the media library could be wrong… Here are image url examples:

https://panamaenglishserviceproviders.com/wp-content/uploads/IMG_0001.jpg
NOT working

Working link (same link as above) – replaced the ‘/uploads/’ with ‘/themes/classifiedstheme/thumbs/’….
https://panamaenglishserviceproviders.com/wp-content/themes/classifiedstheme/thumbs/IMG_0001.jpg

https://panamaenglishserviceproviders.com/wp-content/uploads/Panama-Travel-Corp-Brochure.pdf
old doc, NOT working

https://panamaenglishserviceproviders.com/wp-content/uploads/Yachtwallpaper-e1434730329649.jpg
working (new)

https://panamaenglishserviceproviders.com/wp-content/uploads/0811.jpg
old image, working?

I am very confused about these issues, but sure they are all related to one cause. I have deactivated all plugins, check the permalinks, deleted all the themes I had downloaded that I was previewing, consulted with Godaddy hosting technical support who were not able to assist, other than resetting permissions for the upload files and then referred me to WP Support Forums… I have been searching the support forums for any issues like this and found a few however many don’t seem to be resolved and are not quite the same as my issues here…

Can anyone assist me in these issues? And figure out why it happened? I think it might have had something to do with previewing the other themes broke something somehow??? Weird because nothing was published or activated… Everything was working fine before that…

Thanks y’all.
Mac