I am obese (5-6, 272), i smoke lightly, i have sleep apnea due to deviated septum, i have had fulkerson knee surgery on right leg and need it o. Left knee to. Im having pain behind knee without swelling, yet im laying in bed and it burns. Injury or blood clot? I have a sedentary job but an a caregiver who is constantly on move running errands, coiking and cleaning