Practice Joy to the World (rehearsal letters C to D and F to G) as well as Jingle Bells (exercise 37 in your Essential Elements book). Remember to relate notes to each other instead of just trying to figure out each note individually (if you know a note is C, and the next note is just one step above it, you know that next note must be D without even having to go through the sayings for the lines and spaces).  Keep up the great work!