Welcome to HCM,
You have not mentioned what kind of Tuberculosis you have, I presume it is in lungs and you have taken treatment for it for 6 months.
You have not gained weight and still have problem then possibility is treatment failure which is due to irregular treatment by patients.
If you took treatment regularly then it may be due to drug resistant Tuberculosis
then please consult a Chest Physician and get your Sputum culture
and sensitivity test.
Depending on result of test Second line treatment of Tuberculosis may be required in your case.
Take care of diet taking good amount of protein and high calories in diet and be positive and if you are still sick you have to take treatment.
If you do not take treatment then disease may progress .
Hope your treatment works and you improve soon.