I failed in the test of my most advantageous subject. I feel like I can’t face the teacher.

"Using wine to soothe your sorrows will make them worse." If you can't calm down, read some books and magazines such as Digest, Reader, and Humor, listen to light music or take a walk on campus (it's too cold now, so you can still go for a walk if the sun comes out), and find a close friend. It's okay to tell... After your mind calms down, you should reflect carefully and see where you have lost points and what are the reasons for the loss? Is it because you can’t do it (because you are top-notch in this subject, so the possibility is very low), whether you grasp the time well, whether you are careless (wrong calculation, wrong reading of questions, incomplete steps, etc.), whether your mentality during the exam is the best. Well, you won't make the same mistake next time. In addition, make a post-exam summary and self-summary in time. I believe the teacher will understand you. This is also a valuable experience, don’t be discouraged, I believe you will succeed!