Ankles are slow to heal up, theyre also a pretty complicated joint that docs often misdiagnose. i sprained? an ankle pretty badly once and it took 10 years to get to 97% recovery.
but if you're seeing zero progress after 5 mo.s you should be seeing a doc about it. potentially you may have fractured your talus, x rays sometimes miss that. the bone would set over 5 mo but maybe poorly. Fusion is often presented as the best option but if you can find an exceptional orthopod they should be able to offer other ideas to keep it moving.