I had a hemi-thyroidectomy about 8 weeks ago and have the exact same degree of swelling as when I left the hospital. Some days are actually worse than others. It's a disconcerting feeling - particularly when I have to swallow - I need to keep my head bent forward to do so with any degree of comfort. The surgeon (with whom I have a 3-mo follow-up appt in May) said to apply heat and massage daily. Nothing seems to be working - but at the same time, no one at the Dr's office seems to regard this as unusual, either. I'm guessing it's just going to take time..(?)
It may take 2-3 weeks for swelling to go down, if it is increasing, let your surgeon know.