How can I get a second review of my grades?
You can petition the head of the department/program if you think that your professor has a conflict of interest and can apparently not be fair in grading your class. But you have to be prepared for the department head to then ask the professor what his opinion on the issue is -- and in all likelihood, the professor will say that nothing untoward is going on and that he/she can be unbiased and fair.

In other words, if you're asking for the judge to be removed from the trial, you better have evidence. For example, you probably want to make sure that other students can corroborate your claims.

I'm saying this because as professors, we see students claim all the time that they are treated unfairly -- but in the vast majority of the cases, they're just not very good students. So expect that just making such a claim will, alone, not get you very far. You'll have to have evidence.