We can't diagnose but nerve impingement in the lower back - which causes sciatica and other things - can cause nerve symptoms in the legs and feet. Other things (diabetes, other disorders) can cause those symptoms as well.
Here are some early symptoms of diabetes: increased thirst, frequent urination, significant weight loss, blurred vision, itchy skin, and a numbness or tingling in feet.
Here are symptoms of sciatica: shooting pain - often down the buttocks made worse by sitting/standing, sneezing, coughing, laughing - and often weakness in one leg
The fact that you have it on one side and have weakness is suggestive of sciatica. You'll need to get this checked out at a doctor to get help.