Hello, You are experiencing severe pain on the outside top of the left foot, it may occur due to various causes like stress fracture. It is a slow onset pain that may worsen over time. It commonly occurs in high arched feet. Get clinically examined by a GP / orthopedicst, get X-ray and MRI done. You will be treated accordingly. You are presently suggested to keep your affected foot at rest. Keeping the foot immobilized in a CAM (controlled ankle movement) may get relief. Bone healing often takes 6-8 weeks time so have patience. It can also be due to nerve compression, can cause lateral foot pain, tingling or even temporary numbness to the lateral leg and foot, called neuropraxia, it resolves by itself with time. You can apply pain relieving ointment, gentle massage may help. Sometime, ankle sprain may also present with such symptoms, ice compression may help. Keep it elevated and at rest. You can take Naproxen or Combiflam, one SOS when needed to get relief from pain. Get clinically examined get investigations and tests dome to rule out arthritis or any other bone disease, Get treated. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Nupur K., General & Family Physician