A really amazing thing happens when you lock into the emotion of your song and stop thinking about technique -- you can easily hit notes that might be a challenge for you. Why does this happen? First, because since singing is 90 percent mental, when you stop thinking about your problem notes, your emotion gives you the vocal power to hit those notes easily.
Second, when you're singing in the emotional moment, your fear disappears! Fear keeps you from going fully for a note, and without total conviction and full support, your fear will keep you from your best performance.
So get into the emotion of your song, stop thinking, and let your voice fly free!