I can’t give you a study planner as I don’t know the time you have available to study. I’d recommend that you practise the questions as much as is possible as I’d have thought your technical knowledge is pretty good if you’ve done the exam three times already. The reason you must be failing is exam technique. Your technique can only improve if you work the past exam questions to timed conditions.
If you get stuck on anything technical then you know where we are.