Don't worry la! I think it's due to the teething of the baby.
My baby is the same, she had cold before, taking medicine, and has teething at the same time. Before, she had 5 meals per day (same as your baby) and everytime seeing other eat, she want to eat also. These few weeks, not much appetitie, even for her favourite biscuits, she doesn't want to eat........and I see 2 big teeth are coming..........
Just let her la, it will become normal after the teeth come out...........