It sounds a bit like a severe sinus infection - are you getting any pain in your face at all?
Sometimes my migraine starts with a sinus type of pain, which hurts when you bend forward and also feels like my upper teeth/gums are hurting if I open my mouth wide.
I was told to try steam inhalation to relieve the pain, but the only thing I have taken that comes close to helping is cold & flu sinus tablets that contain a decongestant.
I do not get a blocked nose when I have this pain, so it could be mistaken for a migraine?
Have you consulted your doctor - they can usually differentiate between sinus/migraine pain, and will probably be able to give you something like triptans if it is migraine.