Failure at login page – it simply refreshes

I can not log into my website anymore – neither can the other admin user. When I enter the user/password and click “Log In” – the page refreshes and the fields clear. Through searches I’ve found steps that seemed to work for some people to fix the problem but it doesn’t seem to help me. I have cleared cookies and cache, renamed plugins folder, renamed htaccess.

I’m not sure what else to do. I need to get access desperately. Please, has anyone had any success rectifying this problem?