You may like to think about having some 'mindless nibbles' on things like nuts and dried fruit. By just nibbling at them you won't be filling yourself up, but they will provide plenty of calories and the nuts will provide healthy fats, protein and fibre and the dried fruit many nutrients including fibre. Done regularly, you may find that you discover you DO actually have an appetite, but your brain had switched off the sensor and forgotten to turn it back on.
It wouldn't hurt for you to make an appointment with your Dr, too, to see if there is something going on which could be causing/aggravating the problem. Depression is one such condition that can cause this, as can certain medications. There are many other things that can be checked, including bloods to see if you may need some supplements.