Hi @marybeth,
As seems you have turn on Dropbox Computer Backup. Most probably, unintentionally you turned it on by clicking Yes on some question without payed attention what actually it means. Be more careful in future! Just turn this feature off (take a look on referred help topic) and your issue will gone. 😉
Hope this helps.
Add: Make sure you haven't left your files/folders within Dropbox, but restore them to the original places - chose the proper options.