Rinsing the mouth out with a solution of warm water mixed with 2 to 3 teaspoons of salt can help a toothache. The salt will help bring out any infection that may be in the tooth, as well as lessen the inflammation but always better to see a dentist for long term relief
You really should go see a dentist becaus there could be a severe problem. You could also try using oragel for the pain right now and then a sensitive toothpaste for sensitive teeth. One of my teeth bother me when I eat something cold or hot so I just use Armand Hammer sensitive toothpaste which helps with the sensitivenes of my tooth. Good luck and best wishes.