Hello and welcome to Healthcare Magic. Thanks for your query.
A sudden loss of appetite can be due to various causes. There can be medical causes like gastric problems, liver
problems, endocrine (hormonal
) problems, etc. as well as psychological causes like depression
. You have also mentioned that you feel tired and unrefreshed after sleeping. This could again be a pointer towards depression.
However, it is important to have a proper evaluation in order to ascertain the cause of your symptoms. So, I would advise you to see a doctor for a detailed physical examination and certain investigations, if necessary, so that further treatment can be planned.
Wish you all the best.
Dr. Jonas Sundarakumar