Face pain implies that there was some damage to a nerve, either due to direct impact (if you hit your face!) or something internal like a neck injury. Gabapentin and pregabalin are a couple of options for neuropathic pain. I think cardio exercise is supposed to be helpful as well. And it's worth getting your neck checked out, in case the nerve pain is neck related. In terms of how long it'll last, that's highly variable. I still have some pain over a year later, but it's more mild than it was. I probably saw the most improvement over the first six months.