Hi Peggy,
Sorry to hear that. Unfortunately, this is a tricky one to troubleshoot.
If you're unable to drag and drop WordPress widgets, it's likely because there is a Javascript conflict — usually because of a theme or plugin that is using their own Javascript library, and causing the default Javascript library that ships with WordPress to stop working.
One way to troubleshoot it is to disable plugins one at a time, testing the widgets panel each time. Using this method, you should be able to determine which plugin is causing the conflict.
Please be sure to first create a backup of your site, so you can revert back to the current state if necessary.
Hope this helps!