First 2 attempts 82% and 84%. Please help with some guidlines.

I need some guidelines about preparing for the PSM I certification. I studied the guide and a number of books and I do consistently score 100% on the open exam. However, I tried the test twice and failed. First attempt 82% and second one 84%. Needless to say this is very hard to accept, especially failing for just 1 point.

Is there a strategy I could use that will take my knowledge beyond this and closer to 100%? I really cannot afford to waste another $100. My first language is not English so I guess this does not help either, however, I am sure I can prepare more deeply in such a way to go closer to the 100% mark.

Is there an online test facility (even if a paid service) that provide question styles closer to the PSM I (the open test is a bit far in terms of difficulty) and provide feedback on how you answered?

The Scrum.org feedback provides only statistics and this is not helpful at all, especially since in my case there is no correlation between the 2 exams:

Exam 1:

Scrum Framework 85%
Scrum Theory & Principles 80%
Cross-functional, Self-organizing teams 71.4%
Coaching & Facilitation 100%

Exam 2:

Scrum Framework 92.5%
Scrum Theory & Principles 70%
Cross-functional, Self-organizing teams 78.6%
Coaching & Facilitation 83.3%

Any guidelines are highly appreciated. Thank you.