I am in great pain although the cause is not there

Three years ago I took my papers from the university hospitals to the ministry of heath to shift my work place but I was shocked that it is impossible because there was a missing step of application that should have been done a year earlier. They told me that there is no way to be accepted in any hospital of ministry of health because of that. It was deep enough to crack my heart half. It was like " القشه التي قصمت ظهر البعير" . I made many trial to fix it but it was over , there was no way to back to work. I kept staying alone in my room for a considerable period of time and i felt a nasty depression slowly sneaking my heart through the crack. Once I was calling the ministry of health as a routine check and they told me that I can apply again because they need doctors because of COVID-19 crisis. I hurried up and applied and I was accepted back to work. Though the depression still there. It keeps beating me till now and I have no clue why it is taking advantage of me and it is nasty. I try to forget and remember the successes I make every day , the achievements but there is no way to break free 💔. Have you been through such thing before and how do you deal with it ?