Site freezes after plug-in use/installation

Before anything – yes, I updated WordPress.

For days i’ve been using a photo widget theme (thumbnail gallery) and it hasn’t been uploading any photos, it just freezes and then it doesn’t let me view my admin page or my website for an hour or so. I’ve downloading and tried installing a new photo plug-in but that did the same thing. I’m on a pretty new/good computer so I don’t believe it’s anything on my end, physically. Is anyone else having this issue? Any help will be greatly appreciated ??

Also, Ready! Backup won’t backup my files either. Not sure if this is all a part of the same problem. This happened before and after I updated WordPress.