Andre,
I'm sorry to hear it - failing the PMP is incredibly frustrating when you feel like you've been studying tirelessly and that you've done all you could do. I was in the same boat when I studied for nearly 3 months nonstop only to fail. I passed the next time two months later with AT in all categories, with some major revisions to my study plan. Here is what I can recommend to you.
First, acknowledge yourself for taking such a difficult exam. Take comfort in knowing your passing rate next time will be higher, because, thanks to PMI, you'll know your weak spots and strengths to have more targeted studying Definitely take a break before all of this, so that you're not burnt out.
I also highly recommend using more than one source to study. The PMP is a situational exam, and passing requires understanding to apply the frameworks into a variety of contexts.
Fortunately, there are an overwhelming amount of resources to choose from today, from mobile apps to online training academies. Using an array of applications is a safe way of knowing that you really know your stuff, no matter the source in question. Based on what worked for me, what I can recommend is to use a blend of apps, books, flash cards and online tools. I would reread, make index cards and then would take targeted quizzes based on those areas.
While creating the process chart helps, it is good to get really comfortable with the ITTOs and their relationships. Since the exam doesn't directly ask for the definitions but rather things like.. "what should the PM have done instead?", understanding the process in question the relevant ITTO will gear you to the correct answer.
I was initially baffled when I failed the first try, mainly because of how I had been acing the practice questions in the apps. As I soon realized, while I was improving over time, it was because I was actually memorizing the questions and their answers limited to the sources I was using -- rather than thoroughly understanding the processes.
Another thing to recommend, is taking mock exams in simulated environments. It sounds like this is what you've done, but recreating all of it -- from the meal you eat before to the time you take it -- builds a sense of routine and familiarity with it. Make ‘process of elimination’ work in your favor during the live exam, and don’t leave questions unanswered. Also, when reading the questions, always read the last sentence first. Much of the time, this will help clarify the answers for you. In making the best selection, I suggest reading the last choice first, just so you are less inclined to pick the first answer you see. Try to eliminate two answers if you can, before making a final selection. This will help reinforce the answer and why you picked it.
You got this!