Extremely nervous/borderline neurotic about finals even though I should be set for As

Freshman Biochem major here. I have only two finals: M408C and BIO311c. For context, I’ve gotten a 94 or higher on every test I’ve taken this semester with regards to these two classes. As such, I need about a 70 on the final exams to keep an A in these classes. And yet, I’m genuinely freaking the fuck out. I’m reading the textbooks and doing practice problems for old concepts and I keep making stupid mistakes, and it’s making me frightened that I can’t even pull off a 70 on each final despite studying a week out + getting As on all the midterms. I would appreciate some advice on calming the fuck down, and on how to note make careless mistakes. I don’t want my hard work on the midterms to be end up being in vain