What Causes Pain Under Sternum While Sneezing, Coughing And Deep Breathing?

Type 1 Diabetic, female, 134 lbs, woke up with pain under sternum area (size of tennis ball) in center location, no other symptoms. Pain while sneezing, coughing etc. Would describe pain as 1-10 (10 being worst) a 5-7. Pain not constant usually only with coughing, sneezing, deep breathing.