I Am Having Knee Pain. It Is Both In The

I am having knee pain. It is both in the back of my knee, and on the front side. I stepped wrong onto a curb and felt a straining sensation. I have had soreness for 2 or 3 weeks but it has responded to creams and patches along with Advil. I am concerned since it has continued to be a source of discomfort that it may be an injury. However, if I lay on my back and extend my legs straight up and then bend my knees back down I can hear a grinding sound in my knees. I am having to use support to walk right now. The pain is in my hamstring, and in my calf also. I'm trying not to have to go to the doctor, but am afraid it may come to that.