Hi, Discoverer! From the classes I've taken, Master Lin has said that you have energy blockages, but the blockage could be anywhere in your body so there's potentially no one right answer... I assume you have the original course - do you have the newer course? Which exercises are you doing?
I find dolphining seems to help when I have pain in my lower body. In the Head-to-Toe Healing book, it says that the hip tapping (the one you do during harvesting of the qi) helps with neuropathy and damaged cartilage in hips and knees. Do it for one to three minutes, at least 3x/day.
Also, usually somewhere during October/November Master Lin holds an online healing retreat which I just love! I've gotten rid of some stubborn blockages while attending. 🙂
As always, talk with your Dr, since SFQ isn't intended to replace regular medical treatment.
Hope you start feeling better soon!