My comments

In my team, 3.5 grade out of 5 is highest grade an employee can get. I have been working with one of the most famous news companies for three years. In this period, I have independently rebuilt four complicated legacy software systems alone, but my grades ranged between 3.2 and 3.7. If you are satisfied with your income and working environment, you don't need to worry about the review and try your best to improve your relationship with your boss. Otherwise, you should consider to leave.