Hang in there man. There are actually lot's of people in the same boat as you. I have taken it before as well and failed. I have a similar story to you regarding my clinical abilities, respect from my peers, superiors, etc. And I feel the same way with regards to feeling like I'll never pass. It's a ridiculous task we're given to basically memorize everything there is to know about the biggest knowledge base in all of medicine, so it's perfectly natural to feel like it's impossible to do. But it's not.
From everyone I've talked to this year at work who successfully passed this test, they all said the same thing. Questions, Questions, Questions. That's how people pass this. They just do lot's of practice questions, focus on the ones they miss, and repeat over and over again. Eventually the knowledge will stick long enough to help you pass. This is a test of word recognition, memorization of quick facts, and knowing how to answer their questions. There is no thinking involved. Sometimes there are a few layers of information you have to get through to get the answer correct, but it all still comes down to just having this stuff memorized. The best way to memorize things is to spend lots of time with the topics. The best way to do that is small, regular exposure. A little bit every day over the course of a year is better than spending 8 hours a day cramming during the last month or two.
That's what I've done this time that I didn't do in the past. I've been doing questions nearly every day all year. I feel like I'm finally starting to get a grasp on these topics, though I know there's always more I could do. The last time I took it I focused on board review videos, taking notes, reading and highlighting, etc. I didn't even get through MKSAP qbank all the way through once. This time I've gone through it twice in it's entirety and I've dabbled in UWorld a little as well. Probably over 2500-3000 questions studied at this point. Even though I lack confidence in myself for this test, I take comfort in knowing I've done a lot more this time then years past. So, I'm hoping it's enough to pass. Compared to my peers, I've done at least what they did to pass if not more. If I at least see a dramatic improvement in my score, but still fail, I'll be encouraged to try again. Hoping I don't need to though. I have noticed that just staying positive helps a lot. When I get frustrated and start getting angry at the questions, I tend to miss more. My plan if I fail is to immediately start doing 10-20 questions a day from a different qbank and try again.
FWIW, my first run through MKSAP I did open book tutor mode. That helped me stay positive because I wasn't seeing myself miss so many questions and it also helped me learn because it forced me to read through BB to find the answers. This second time through I'm doing closed book sessions in timed mode and I'm making flash cards for facts that I need to know, but still miss. I'm consistently averaging 78% correct now. I've been trying to boil each question down to it's unique, key point, which is usually just a one sentence fact. Such as, "6 weeks is the length of therapy considered adequate for a trial of antidepressants." Or "the best way to check for Giardia is a Giardia antigen test (not ova/parasites)" or "Certoluzimab can be used for Crohn's disease in pregnancy" or "Dermatomyositis is associated with an increased risk of Ovarian Cancer"
Almost every question can be put onto a simple flash card when you boil it down to what they're actually asking. That's how you make this test doable in my opinion. Assuming there are 205 questions on the test after they subtract the experimental qs, and assuming you need 70% to pass (which of course we don't know for sure), then that means you just need to know 140-150 facts like that to pass. So, memorize 200-300 of the most high yield facts you can find and add that to what you already know from your clinical training/experience and you should be good. That's an acheivable task in my mind. This is what I've been telling myself to help me get through this. Hopefully I'm right.