I have a persistent hunger feeling that hardly goes away, however, I have lost my appetite, so I never feel like eating. I used to be able to eat anything whenever I was hungry and in a few hours, eat again and feel normal and full and satisfied. Now, I force myself to eat even if I don't feel like it because I know to be healthy I must. Even when I eat enough food that would normally make me feel full, within 15-20 mintues, I feel a nagging, burning hunger feeling again. Sometimes food is even difficult to eat because my stomach begins to feel uneasy and unsettled. What can cause this? Also, I have never had these issues before until the last couple months.