You wrote that you were absolutely unable to do anything despite trying. I think that fits. More severe cases of burnout or depression can extend this to basic

You wrote that you were absolutely unable to do anything despite trying. I think that fits. More severe cases of burnout or depression can extend this to basic activities such as eating, hygiene or even speaking - some people may be unable to speak back despite hearing and understanding others. Such cases of course require immediate psychiatric in-patient treatment.