I am experiencing aching, nagging pain in both legs, from top to toes. Especially very bad at night when I need to sleep. Just had left knee replaced Feb 20th, but developed cellulitis on March 11, with extreme swelling and pain. My doctor gave me Keflex for 10 days, 3 daily equal 1500 mg. Cured, but now my knee is like frozen and I have difficulty with therapy. I am exhausted. I am 75 years old, was active, now no interest of energy to do anything.