Can allergic reaction to fruit cause a pea-size lump inside my tongue? it's tender but not painful, slight swelling. what can i do?

See your doctor: This is one of those problems where a visit to your doctor is necessary to figure out what's going on. Only after a thorough evaluation, including examination and possibly labs and other tests, can your doctor correctly diagnose you and treat you effectively.

Sounds unusual: Many allergic reactions cause mild swelling and frequently cause itching. Tenderness or nodules is not a common symptom of allergic reactions. A thorough physical examination by a doctor would likely lead to the answer.