Sorry that your doctor cannot get you an appointment! With lingering pain, you should definitely follow-up, especially many months post-surgery. You might consider seeing a different doctor, as a fresh set of eyes might be worthwhile. Your pain might be indicative of your post-op physical therapy being inadequate. With your ankle pain, you might also want to research the symptoms of complex regional pain syndrome. This awful condition caused me to have pain, weakness, ultra-sensitivity, and skin/nail changes in my toe after back surgery, as odd as that sounds. Pain management doctors diagnosed me, after a referral from my back surgeon.
I hope you get seen and get some relief.