Swelling feeling UNDER tongue?

My tongue keeps feeling swollen underneath, sort of at the base where the floor of the mouth meets the tongue. Only on the left side. It doesn’t LOOK visibly swollen to me.

It will come and go. I do have burning mouth as well which also has been coming and going. Antihistamines don’t seem to help.

Does anyone get tongue swelling on the floor of the mouth just on one side? Does this seem like it could be an allergy? I’ve had pretty extensive allergy testing done and nothing has really popped up. I’ve also don’t elimination diets. It doesn’t seem to be triggered by food, but more smells??

Wondering if anyone has experienced something similar, like undersided tongue swelling on one side.