woollyhead

i have been taking Levothyroxine for about 8 months. i initially started on 25 mg and soon after increased my dose to 50mg. during this time I suffered from what I can only describe as woolly heads, feeling as if the top of my head was blowing off and a ringing sensation in my ears. i have also had palpitations which are worrying, and terrible temper outbursts. the doctor increased my medication about 3 months ago to 100mg and up until a few days ago I felt better than I had in a long time. I now find that my headaches and the ringing sensation in my ears have returned. has anyone experienced the same problem and how did you cure it if at all. Denise