I Have A Sharp Pain Along The Outside Of My

I have a sharp pain along the outside of my left hip in connection with a sharp throbbing pain in my left knee. It only materializes at night in bed, and usually after I have been asleep for 4-5 hours. The pain subsides when I lay on my back but is aggravated by laying on my left side. I assume this is sciatica and have been trying to stretch out the muscles in my back. Any suggestions to additional treatment?