synthroid med

My regular doctor had to quit his practice to to health concerns. He had me on synthroid 137 mcg. Recently I had my thyroid checked and my new doctor said it was low and changed my dose to synthroid 112 mcg. Does this seem right? I would think the dose number should be higher?? I have only been taking this new dose for a couple of days, but before when I was on 137 I got really tired almost like I could close my eyes where ever I was and just go to sleep.