I have been suffering with cough last two years, every time with antibiotics it's become noraml, now I have done chest xray, ct scan for chest and motuox test for tb, its became negative, but last 15 days I have last 5kg weight and night time I am getting fever still,now I am using beutool 200mg through inhaler, now I am feeling ok but night time I am getting low fever, could you please suggst me. What could be the problem.