Hi Angela,
To narrow down the issue, I'd like to confirm the following information:
1. What is the version of your Mac?
2. Regarding "after several days it lets me back in", could you please send us detailed information?
3. Do you download the suite from Office 365 portal? Have you installed the latest update for Microsoft Office 2011 for Mac?
4. Can you provide us with a full screenshot of the error for investigation?
To upload screenshots, click Use rich formatting in this thread and select Insert/Edit Media.
Regards，
Hale