Welcome to this Forum.
Your description of pain is partially clear. The pain which increases on walking could be a soft tissue
origin. It could be a cartilagenous, muscular or tendonous in origin. I hope you were not hurt and it is a gradual pain as your history has no description of that.
Chondromalacia is typically seen at your age and suits your description. Taking a Over the counter pain killer is better and if it does not help seek a doctor's help.