What Causes Severe Pain Between Knee And Ankle While Diagnosed With RLS?

Hi, my name is Dennis from Ontario, Canada. Broke my left leg 50 years ago as well have suffered with back problems from driving transport with on and off again sciatic pain, as well have had restless leg syndrome for about 15 years. I have recently retired in October and have traveled to Florida for the winter. For the last 2 weeks my leg is acting up bad with severe pain between knee and ankle when walking. Feels ok when laying down. The pain is not sciatic or restless pain that I have experienced before.
Is there any thing I can do to alleviate the pain? I have no swelling or redness on my left leg.

Thanking you in advance
Dennis Cleary