Have you tried seeing a homeopathic medicine doctor. For starters this is natural german form of medicine. You can consult the doctor and take a medicine called Nux Vomica-30 and after a few days Nux Vomica-200. It should help.
ok that should have been To: Taz lover rather than "Runny nose" - sorry..
Well, from my perspective you're one lucky Beee. I have the opposite problem of a tooo dry nose and sinuses, and it's an absolute torment - disabling actually. Not to detract from your situation though.. I once had a too runny nose also - then had surgery to staighten a deviated septum and open the nose some without removing turbinates. I was good for a few years, then started getting beat-up by the dryness condition. -But the point is I know where you're at, and it is annoying.
In my present condition, I see some improvement when eating - apparently because the salivary glands are stimulated and the nose-throat are better moisturized. I'd say this is what you're experiencing and it's normal - just more runniness because the salivary glands release more while eating.. Whatever you do, I'd recommend not having some kind of surgery in an attemp to fix it because there's no guarantee you won't end up with the more tormenting overly-dry problem (this isn't just dryness in the nose - it causes mucus to thicken all the way down to the lungs, and bouts of deep choking coughing in the struggle to expel it).
The runniness should subside as time goes on. Antihistamines are drying and can be used to fix the problem temporarily as needed.