Tongue swelling is a disturbing symptom. Allergic reactions that you are describing become more severe, as tschock wrote. Ask your doctor about getting an Epi-Pen. It could save your life. I am aware of patients with shellfish allergy that had a serious allergic reaction while eating in restaurants when other people were eating shrimp.
Keep a diary of your foods and your symptoms. You may want to include your activities(i.e. cleaning birdcage, doing yard work) and locations(i.e. brought niece to Petting Zoo, visiting aunt in her dusty house) Read the ingredients on labels and note them. It is laborsome, but essential in order to identify allergy. Your allergist may order allergy tests, including food allergy testing, albeit there are many false-positives with food allergy testing.
You could eliminate a food from your diet and see if you remain symptom free. Then reintroduce that food to determine if that is the trigger.
Again, I must recommend you ask your health care provider about the Epi-Pen.
You don't mention your age, but I'll assume you are an adult.
As we age our bodies go through many changes...as do our allergies.
Many people who have never had an allergy to anything suddenly find that they appear to be allergic to everything. Not quite everything, but it seems that way.
An allergic reaction can occur immediately or it can take a day or more to show up. It may not be anything you just ate...it could be something you came into contact with a couple of days ago.
Have any of the things you've eaten in the past few days contained the same ingredients?
For example:did you eat a bag of peanuts a few days ago, a peanut butter sandwich yesterday, and peanut butter cookies today?
You'll need to either keep a diary of what you've eaten/touched for a few days to a few weeks and see if there's a connection, or you'll need to see a doctor and have allergy tests done.
Be warned though, it may take up to two years to get in to see an allergist...depending on where you live that is.
I would still see a doctor though...swelling of the tongue is a bad sign...it could swell so bad that you could choke to death.
My mouth had the same reactions whenever I used take a certain antibiotic. My tongue would also crack and bleed as it swelled.
Good luck in your research.
One more detail: the reactions are always happening after I eat, almost immediately.