Hi @Eddie, I am sorry to hear about this!
I recon you tried accessing your Dropbox account, and did you come across any errors?
Did you also receive an email stating your Dropbox email or password has been changed? It's important to note, that it will be wiser to reach out to Google, in regards to your Google account, so they can guide you and give you the appropriate next steps.
Feel free to have a look into this Help Center article too.
Let me know more!