First off, I would say you have to recognize the enemy and how he operates. Who or what is it that causes you to feel this way? You already know that it happens when you want to minister in song, so you can prepare.
Some of the things you can do is have a private devotional time as close to when you know you're going to be ministering, clear your mind and focus on your purpose. Listen for what God wants to say to you, and get focused in on him and how he wants to use you.
If there are certain people that always get this reaction out of you, then practice not reacting to these triggers. It's easier said than done, but when you know it's the enemy, then you know that you have authority over him. When these tactics stop working on you, then he'll have to come with something else. Then the cycle starts all over again
