Hi Nick
As a physio who has previously specialised in pain management, and has also had complex regional pain syndrome (AKA RSD), I would strongly suggest sorting out a diagnosis of the underlying injury/ problem with your consultant, and getting that managed properly. I am surprised you have been given a diagnosis of RSD without a diagnosis of the other, unless they have ruled out a large number of other potential problems (in what sounds like a very short period of time). It will be difficult for you to know/ judge how much is safe/ not to do with your affected leg until this is done. To my knowledge there is still a huge degree of uncertainty regarding the reason some people develop these sorts of problems and others don't.
Once the injury is sorted (diagnosed or treated depending on the problem), and if you still are having problems, ask for a referral to your local specialist pain team. They will be able to diagnose the CRPS/ RSD, and help with management strategies, as well as the medication if you need it - see above. You could try googling 'mirror therapy'/ 'mirror visual feedback' to get an idea of what you could try.
Sorry for getting technical...
Matt