To dream about hornet is interpreted as the symbol of danger that the dreamer is going to face. Perhaps you gave up too fast. You need to pull yourself together and deal with the harsh situations in your waking life. If you have been stung by a hornet, then such dream represents the revenge you are going to give. You do not want to forgive and cant forget the harm someone made to you.
Read more about dreaming of Hornets in other dream meanings interpretations.