Give the c1 c2 adjusting more time.
Does chiro do other adjusting or soft tissue work along with the upper cervical work?
You could be having some neck muscle spasms or tightness that is pulling things back out of alignment so some ultrasound, massage, low level laser might be helpful also.

Eat healthy rest and try to de stress as best you can.
I know it is hard when your young , but be patient, some times these injuries just take time..

The fall may have also aggravated an old sport injury that you never really noticed before..