What could be wrong if i have a soft patch on the roof of my mouth accompanied by difficulty breathing?

Airway: Everyone has a hard part and a soft part of the palate (roof of the mouth). If you are having trouble breathing you should see a doctor right away. There are many conditions that could cause this, including airway obstruction in the back of the mouth and throat, lung disease, and heart disease. I would need more details to begin figuring which it is. You should be seen.