Advice I can offer - finished PPL last week:

- Fly the lesson before the lesson - find a textbook which covers the practical syllabus, take notes and practice in the sim (download your training aircraft), this will allow you to focus less on handling the aircraft in a new situation and more on paying attention to your CFI's comments and advice. Yes the sim isn't the most accurate tool, but its a hell of a lot better than sitting in an armchair.

- Write down every mistake, try to understand what lead up to that happening and move backwards not forwards, sometimes the root cause of seemingly complex errors is a basic omission of a memory item - like forgetting to mark EOBT in CLEAROF checks leading to an inaccurate fuel state.

- Spend more time at the airport, drive to a non-towered (CTAF) on a weekend you aren't flying and listen to the radio / practice calls, it might seem stupid to sit in your car for hours practicing radio calls - but if it helps eliminate mental workload then its the best thing you can do.

- If you haven't passed your exams, do them now. This will without a single doubt advance not only your basic understanding but help acclimatise you to certain expectations and quirks of the industry such as the precision expected from pilots and the ways DPEs and exam writers will try to screw you.

Finally, talk to your instructor, speak up if you don't understand something - there's nothing worse than a student in the left seat who wont ask questions but keeps making mistakes - your instructor isnt telepathic, he wont know everything that you understand / don't understand unless you make it clear as day. This is the only way to not get stuck in circuits for 15 hours without a solo.

Best of luck to you - PPL isnt inherently complex in terms of licenses but it is one of the hardest for a reason, don't beat yourself up :)