I cannot log into my email account on Gmail which I just used 10 minutes ago. It says it is a security issue which I can do nothing about. How am I supposed t

I need to know how to keep Firefox from blocking my access to my gmail account. I used my gmail 10 minutes ago without incident and need to access it again to conduct business. Now I try to get a document I was just using and it says there is a security issue with google preventing me getting into my gmail account. What can I do? This is ridiculous as I was just using it. Thank you.