It can take longer than 1 week for the stitches to dissolve. Don't worry about that. If you find it uncomfortable, then I would recommend that you call the surgeon that removed your teeth and have him look at the area and remove the suture if necessary.
Your symptoms are classic for Acute Alveolar Osteitis or "Dry Socket". Of course without examining you this is only a VERY educated guess. "Dry Socket" is when you dislodge all or some of the blood clot in an extraction site or the clot breaks down on its own before it matures. This...
I would advise you to go back to the oral surgeon to evaluate for infection or for possible "dry-socket". Both conditions could cause severe pain. It also might be the normal healing process. Let the surgeon decide for sure.