Keep continuing finger movements and hand physiotherapy especially your thumb . Your wound is already healed . You may have itching over the wound that can be treated by over the counter antihistaminics like Avil or other drugs like cetrizine or allegra . Try massaging the scarred and burned area with Vaseline or coconut oil that will prevent development of Hypertrophic scar.
Health Tips
Recovery of the color will take time , it may be hyperpigmented over time.