I spoke to one of the PMs today and she's quite dubious about my condition being CRPS, due to the relative mildness of the symptoms, although she also said that it can be more or less severe. Anyway, we agreed to give up on the acupuncture and I'm to get gabapentin from my GP for two months before re-evaluation.

Interestingly, I've managed to get a bit more relaxed this afternoon, which is definitely linked to less pain in the knee. I really think it's worth working (if that's the right word) on that.