Why does my gland swell when i eat...?

When i eat anything with a strong flavour, like cheese, or chocolate (anything that makes my mouth water quite a bit) my gland swells under my jaw really big, bigger than a golf ball. It's quite uncomfortable and i have to stop eating. It's only on one side. After stopping eating the gland will go down in about 15 mins and feels a little bruised. I have had this a few times before, it lasts for a few days then goes. But this time the gland is bigger and it seems to be lasting longer. Should i go to the doctor?