I am currently learning Rachmaninoff’s third piano concerto and whenever I get to the pages that are tricky, I get distracted by other stuff and just kinda quit. How do I avoid these distractions and learn the piece fast?
I would start by creating an environment with just you and the instrument. This means eliminating all distractions by placing them outside of the room. Silence electronics and schedule breaks if it helps, being strict about when the breaks start and stop.
Listen to the piece several times before taking steps to practice it. This will help you learn the piece step-by-step by providing a 'correct example' to work towards.
When practicing a difficult piece, I start by isolating 2 beats, adding an eighth to the end, then moving on to the next two beats, and so on. By overlapping sections like this, it makes it easier to play them as a full piece once they are learned.
I then play it normally, adding a swing to it in two ways - two eighths equals a quarter triplet and an eighth triplet, and vice versa. This lets me play at normal speed, but transition between half the notes at a faster speed, and the other half playing the other way.
I hope this helps - this is my method to focusing/learning pieces quickly.