13 weeks after ankle sprain. No fracture. Still pain at inner ankle when walk. Doing ankle exercises n physio. What else can doc do for me to recover?

Immobilization. You many benefit with having it immobilized for a while.
Re- evaluate. To check for any occult injury.
OCD? This sounds like it could be more insidious than just a sprain. One option is to obtain an MRI of the ankle. Often times osteochrondral defects or tears in the peroneal tendons can seem like a sprain but need some type of surgical intervention. Ask your physician for an MRI of the foot and ankle.