I Cannot Login To 2 Of My Gmail Accounts. I Use The Same Info I Have Always Used

This is my second day trying to access my accounts; [email protected] and [email protected]. I get error messages everytime I try to access the account. Most often the error message say that either my username or password is wrong. Other times it says that I changed my email address even though I know I didn't. then I try to fix it and I should  go to password-assistant page and when I do that I repeat the same questions. It is like groundhog day, over and over the same thing.