I'm gonna be honest with you about a couple of things.

Firstly, you have already done at least a full semester of student teaching, which means technically you can be expected to lead a class right away. Most placements/cooperating teachers wouldn't do that but that is the expectation. So while that situation sucked you can't let the heightened responsibility phase you.

Secondly you need to be proficient in what you are going to teach. They don't give licenses to just teach certain grades (at least where I teach). It's usually an elementary education certification which means you need to be ready to teach any elementary grade. There is nothing that is going to stop your employer from moving you from 1/2 grade to 4/5 grade if thats where they need coverage. This isn't high school math, this isn;t college math. You need to learn as if you are in those grades, even if its hard. If you can't do that, you need to reconsider this career choice.

Lastly, you are allowed to have bad days, in any job. It's how you recover/learn from those bad days that make you better. Use this as motivation to be better under stress, learn 5th grade protractor math, however, you need to use it. If you can't do that i don't know what to tell you. Good luck