"Mental agony" refers to an intense and distressing feeling of suffering in one's mind or emotions. It describes the pain, anguish, or torment that someone experiences mentally. Full definition
As per the court order, the insurer will now pay the outstanding amount to Ramesh Prasad along with a fine of Rs. 5,000 as for causing mental agony and litigation expenses of Rs. 5,000 within a month. (policybazaar.com)
What sort of world is this that predisposes roughly 20 percent of human beings to suffer mental agonies? (religion-online.org)
When I was anorexic, the constant mental agony was so intense that the only relief from it was physical pain. (newscientist.com)