Hi thanks for posting your query.I have gone through your details .Here are few effective remedies which you can follow for gaining weight -
Have chyavanprash daily in the morning.
Soak 10 raisins,10 almonds overnight and consume in the morning.
Have banana with milk twice daily.
Boil milk with almonds,dates and drink.
Take 1 tbsp
ashwagandha and 1 tbsp shatavri churn with milk twice daily.
Have more dairy products like cheese,paneer,ghee,peanut butter in your diet .
Eat 4-5 small meals a day.
Boost up your appetite by walking daily for at least 20 minutes.
Take a light nap after noon meal .
I would recommend few ayurvedic preparations like chyavanprash,ashwagandha valeha,shatavari
kappa,kushmanda avaleha,yastimadhu.
Practising few
yoga asanas help in gaining weight
Sarvangasan,shavasan,bhujangasan,yoga nidra.
Hope you find this answer useful
Wishing you good health!
Regards
Dr.Pallavi