What you are having is decreased appetite due to psychological reasons. another cause could eb depression. There are various signs and symptoms of depression. Common are feelings of helplessness and hopelessness, Loss of interest in daily activities (hobby, pastime, social activities, etc), appetite or weight change, sleep changes, irritability or restlessness, concentration problems, etc.
The three most commonly indicated treatments for depression are psychotherapy, medication (antidepressants), and electroconvulsive therapy. You should consult a psychiatrist to confirm the diagnosis.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.