Answer:
The condition you describe may be compatible with a large subcutaneous hematoma (blood under the skin). Normally these situations resolve spontaneously in some days / weeks and the subcutaneous blood is readsorbed. The treatment needed may depend of the magnitude of the injury, but frequently nothing more than time is necessary.
Without any clinically significant complication, pain or functional impairment, normally no special caution is required and a normal life and activity can be conducted.
However I would suggest an evaluation by a medical doctor to exclude the possibility of any other significant clinical complication.