These answers are all excellent.
The stitch may need to be removed at this point.
Headaches have hundreds of causes and it is difficult to speculate as to the cause of yours. However, if I had to guess, I would attribute it to a tension headache due to pain induced positioning of your neck.
Although you can treat the headache, it would be best for you to treat the cause of the pain (the stitch) and then see if it resolves. If it does not, you may need ot seek a headache specialist.


