It is very important to protect your knees and legs. You should always wear proper footwear and consider all your cardio activities on stable surfaces. You should restrict exercise and cardio on hard surfaces. You should be careful with regard to falls, blows and strikes involving your knee joint.
As you had the fall there is a strong possibility of ligament injuries and subsequent knee joint instability. Get an MRI done and get yourself examined by an orthopedician.
You can continue taking pain killers intermittently and also apply ice packs for relief.
You might be having osteoarthritis as you are taking euflexxa injection which is a highly purified hyaluronan supplement; you can confirm osteoarthritis by a simple X-ray.