my tsh level is 21.what dose of eltroxin i should take?i am 51 yrs old,suffering from this disease during 6yrs,at first it was 50,taking eltroxin reduced the level to normal, now i am taking the dose as 50 mg,recently i am feeling lack of energy and test result is T3 1.12 mg T4 5.46mcg ,TSH21.68 micro IU/ml .i am a male.now advice my dose please.my hight is 5 10\