I experienced this some years ago dawn. Dentist confirmed no decay and advised I see my GP who after a short ‘wait and see’ period referred me to a maxillofacial consultant. I’m a dental wimp so this worried me. The consultant was both kind and reassuring. He examined and diagnosed, saying neuralgia was the closest diagnosis but it wasn’t true neuralgia. There was no active treatment other than pain killers and advice to use warmth to ease pain, to avoid very cold drinks, being out in cold wind and very cold weather. He offered ongoing appointments every six months or so for a general check. Mine gradually eased over a two year period. It does recur every now and again but doesn’t last long. I’d suggest an urgent dental appointment and if all clear see your GP. In the meantime ask a pharmacist about the most effective over the counter painkillers. Hope it settles soon.