Auth servers up! but not for my server.... please help

so I tried to log onto my server and it told me the generic " Failed to verify username, session authentication server unavailable!"
so I immediately think oh great the auth servers are down AGAIN. But when I check the auth servers are just fine and all other servers are managing to authenticate their sessions just fine. It seems my server is the only one that cannot connect. I changed nothing about my servers configuration or plugins. I was working fine one moment and now no one can log in. Please help