What should I do to get a normal TSH level?

Hi doctor,

Last year, when I checked my thyroid profile my T3 and T4 were in normal range. But, my TSH level was greater than 150 (normal range 0.35 - 5.50). My doctor prescribed me 100 mg Eltroxin. After three months, my T3 181.7 (normal range 60 -180) and T4 15.2 (normal range 4.50 - 12.60). T3 and T4 levels were higher, but my TSH was well within normal range of 0.37. My doctor changed my prescription to 75 mg Eltroxin. After three months, my T3 113 and T4 7.3 were normal and again TSH was higher, 32. My doctor changed my prescription to 88 mg Thyronorm. Three months later, my T3 and T4 were normal, but TSH was 23.7. Since then, I am on 88 mg Thyronorm and checking the level once in every three months. Always, my T3 and T4 are well within range, but my TSH is higher between 25 and 35. What should I do?