Ups and downs leading up to DEA-C01 test day

Recently I posted about how [[I take the AWS Data Engineer - Associate exam in 5 days]]. My concern is that even though I’ve been studying for a couple months now, when I take some practice exams I am failing.
These failures impact my confidence in my ability to pass the exam this Friday.
Since this post, I’ve continued to practice my failed answers using flashcards. I’ve also been taking a new practice exam daily.
The results on these practice exams have been mixed. After my initial 56% score that prompted me to write my initial post, I studied and waited a day.
The next day I finished the exam and found that I scored an 80% which is a passing grade. At this point I began to feel better, but committed to repeating the process the next day.
So I repeated the process and when I took the next test I scored a 56% again.
I’m continuing to study and review my missed answers and the test is just days away now. I would feel much better if I was more consistent in my scoring. It’s up one day and down the next and I don’t understand why.