Can’t access my own files on Mac

I am also trying to login to my normal files on my computer. I have been denied access, to my own work. All of a sudden. For some reason Microsoft has locked my personal files. I have tried the usual fixes on the drop-down menu, i.e. security and file access and they don’t work. I cannot do my work or access my own accounts and therefore cannot invoice my clients. It’s a disaster. What do I do?