Start from Treble clef with just the melody. The melody is the part of a song where you actually sing. There's no way around this, first, just learn to read slowly.
Once you can easily identify the letters, read a phrase of a song at a time! Phrases are typically identified by long pauses in between, or a resolution, or degree 5 notes. You will know it when you see it!
Just like Tetris, always look ahead! This means reading phrase by phrase instead of note by note! Don't stop to play a note before reading the next one.