Char, If the class isn't actually over yet, don't give up now.
For what it's worth, when I took Engineering Physics II, my recitation instructor would hand us back the tests (usually a few days after the tests were taken). He would also give us the breakdown of the grades: a histogram of how many students fell into a percentage bin, e.g., 0-10%, 11-20%, etc. It's possible that not all recitation instructors did this. It was not uncommon, when I took the class, for more students to receive under 30% than over 70% on any given test. Many (most?) students were were convinced they were failing. But at the end of the course, presumably due to a curve, students received better grades than they thought they were going to.
If it is over, don't give up either. As others here have mentioned, there are ways to go on if you persevere.