Can you get complex regional pain syndrome (rsd) in the ankle after a sprain? i have so much burning pain in the ankle what is the usual treatment for this condition. i am miserable?

Clearly has happened: CRPS, previously termed reflex sympathetic dystrophy, emerges rarely after trauma, and needs to be diagnosed efficiently. Your burning pain could reflect a peripheral nerve injury, or even a small fracture, and this also needs clarification. To start the process, see a neurologist or a physiatrist. You may require a triple phase bone scan, a QSART study, or thermogram to clarify. Good luck.