Rest your thumb with no movement. If the movement is very painful and not able to move the thumb get an x-ray done. If you are able to move with mild pain rest it . Apply cold compress 2 to 3 times not less than 20 min
Wear thumb spica to rest your thumb.
Next Steps
Rest it with splint and cold compress as of now if the movement is there with less pain.
Health Tips
if the pain is not bearable and not allowing any movement of thumb get an x-ray done.