Dropbox says I'm over limit, but I don't see how or why. Is my computer at risk?

So, I WAS using Dropbox Premium a while ago when I got my new computer, it uploaded files automatically and didn't really do anything else significant. It worked. Eventually, I stopped paying for it since I didn't need it. However, it is NOW saying that my account is FAR over the limit (like 7x I think? It says I have 356GB in there). 

HOWEVER, when I click the option to check my folder, or free up space, looking inside there is nothing save for a single mp4 file I needed to share for a college project. It is saying that it will clear/delete whatever is bringing it over the limit, but I'm worried with the current Window's scare involving your files getting perma deleted it will just erase my hard drive. What is going on, do I need to be worried?