If your tongue has become swollen abruptly it would be very concerning for an allergic reaction of some sort. Typical causes for an allergic reaction would be foods, in particular strawberries or peanuts, or medications over the counter or prescribed, even vitamins and herbal supplements.
I would reccomend you take some benadryl and go see your doctor emergently as a swollen tongue can worsen and make it difficult for you to breathe.
If you have a had this swelling progressing for a while it may be due to a medical condition such as an underactive thyroid or an infection of the tongue. While this would not require emergency evaluation it should be evaluated just as well.
I believe the numbness is related to the swelling. You may have a funny sensation of the tongue due to the swelling and stretching of the skin of the tongue. If only one part of the tongue is numb for example the tip or only one side it would be more concerning for a potential neurologic cause such as inflammation or damage of a cranial nerve, although the swelling wouldn't really fit with such a diagnosis.
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