Sorry, did not mean to hit post comment yet.
The labs need to be tested more regularly than that until you are at a more normal level. Normal being 0.3-3.0, whichever is normal for you, depending on how you feel. Some people feel better at 0.3 while others feel more optimal at 1.8.
I also read that staying at a dose to long is not good for your thyroid, and causes somewhat of a setback, if you will. You need to get your dr to check you about every 6 weeks, until you reach a level in your hormones that you feel much improvement.
When your optimal level is reached, then recheck less frequently.
I'm no expert, though some would argue with me(just joking). Seriously, I am no expert, but from what I have read, it seems that with your TSH that high you need a higher dose, and need to be tested about every 6 weeks.