1. any hemoglobin
level or chest x-ray been done?
2. any Nutritional disorder?
3. try to remain calm and happy, because body and mind are interlinked, and this is what we call in Ayurveda the definition of 'Health'
4. You can Improve your Appetite by doing little bit of jogging,brisk walk for half an hour, but in the morning.
5. You can consult an Ayurveda Physician about the medicines helping in improving appetite and gaining weight (Kushmandha Avleha, Chaywanprash,Ashwagandha-avleha/arishta, Draksharishta)