Stressed about english

Im a rising junior and I would like to hear your opinions on a subject that worries me a lot. I am international and Im not a native speaker of english. I have been taking language courses for years and have managed to bring my skill to a very satisfactory level. Also, I am an owner of the Proficiency (C2) certificate which is the highest level that can be achieved in my country (after studying English in college of course). Typically, I am qualified to teach the language in private language schools (for teaching in public schools you need a college degree in english). Anyway, even though I can speak and write in english without any problem and I could live in a english speaking country without facing any issues, english is still a foreign language to me. In order to communicate and express myself, my ability is more than good enough, but on a scientific journal or literacture I face difficulties. I know science and math terms in order to understand the problems I will be given, but on the english section Im afraid I will mess up. Im talking about the SAT exams. It can get difficult for native speakers to understand those texts, imagine for internationals. I know what I can do to get better and I know how being international will generally hurt my applications, but I was wondering: in case my math, science and subject scores are nearly perfect but I mess up my english test will that hurt me a lot? My prospective major is STEM-oriented