Google Mail keeps bumping me off email...constantly. Help?

This is frustrating. I just responded yesterday to @augustlan who was having a similar problem.

However, my problem seems compounded, especially today. I do not have another gmail account opened at the same time. This is my main account and I write an email and attempt to send it, and then it says “Oops, your gmail has expired.” This means, I have to sign out and sign in again. I rewrite the email (or paste it back into the body of the missive) and once again “Oops sorry your connection to gmail has expired.” This has happened at least two dozen times this evening!! Once in a while, I might be able to get one email out, but the it would start again! I even closed all the windows….and still nothing…it did it again.

arrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrgh

What is going on?? Anyone ever experience this? This is ridiculous.