Leg pain below knee at culf, side &

Right leg severe pain at times near culf , right side of culf & below at few spots for last 6 days. Pain while walking and standing for 5/6 minutes. Too painful to walk now (I am a regular walker for 30 mts daily). Pain at rest also but not much. Xray report of 9 month back says: Early periarticular osteophyres are seen with associated mildly reduced medical tibiofemoral changes. However, I dont feel pain at knee and used to walk normally till a week back. Cold compress at pain area gives good temporary relief from pain. No noticable swelling at pain area. Pain spot changes sometimes to below culf towards ankle. I do simple knee exercise for 5/10 minutes daily for last several years.. Sometimes I feel there could be Vit D deficiency, could be muscle cramps... Thought of taking pain killer. But I hate self medication. Pls suggest medicines.