I feel difficulty in breathing whole day since 2 months. And from 1 month I feels like hot inside body especially inside the head and burning sensation in eyes. Muscle and joint pain all over the body. And pain in jaw and backside of neck, these symptoms arises at 11 am and subsides at 6pm. In this time period temperature is about 99.7 to 99.9 And after 6 pm I feel hotness in my hands and excessive sweating in palms and face even at 22 degree Celcius temperature in environment. And my heart beats raise upto 130bpm even at rest and suddenly falls down to below 60bpm when I feel feverish. And my thyroid function test and CRP, ESR,CBC etc blood test are normal and urine routine test are normal, random blood sugar are normal. I can't do my normal activities I feel tired soon. even I can't study properly. Doctor please can you suggest me what may be the problem.