I feel like Im not smart enough for school

Hi guys, im currently about to start my 3rd year of college. And I’ve figured out that I wanted to do nursing my second year. As Ive been taking my classes, really enjoy the material, but everytime i take a test, i DO HORRIBLY. My science gpa is low, it is because I got C’s. I just dont know what to do anymore, the nursing schools I apply for (that are near me) All require high gpas, and I understand it, nursing is competitive. I am currently feeling so down and dont know what to do. I just know when I submit my nursing application for the first time that i wont be accepted, Im saying that because its true, My GPA does not compare to other students. I struggle alot with test taking, Im bad at it, its like as soon as I start the test, I overthink and second guess myself. I dont know what to do because I want to do nursing, thats a dream of mine. I guess my biggest fear is failure and thats all in my head. I need motivation because I feel like the dumbest student in every class I enter.

It takes special study skills, a lot of work and confidence, and you need to maintain your composure during tests. Have you accessed learning services at your school for tutoring? Get help with test taking skills?
Could you retake your science classes?