When i get anxious or stressed i get a symptom which is a lump or feeling sick in throat this makes me lose my appetite how can i get rid or reduce this symptom?

It is not feasible to provide an opinion without additional history, physical examination may be some tests. It would be prudent to see your doctor to see if you may be depressed. Depression is treatable. Counter-intuitive as it may seem, exercise may help. Start with low intensity exercise such as walking and gradually increase the intensity as tolerated. Drink more water. Wish you good health!