After moving to new URL, my Widgets admin page isn’t working

I really screwed up moving the site from an old URL to a new URL. After I did it by just grabbing all the files and putting them into a new directory on my server space, I realized it was all wrong and corrected most of the problems. But now in Admin, my widgets screen won’t show the sidebar & most of the widget options don’t show up. I would really like to use the Widgets section, but don’t know where to fix it.