It's fine, we all make mistakes.
Answer:
I am not worried about the exam. I am strong enough to at least pass.
Explanation:
I believe you wanted a completion to the sentence? Either way don't worry about your exam, just do your best. But doing your best doesn't mean going "i'll do my best" and just hoping you know the answers. Go study! Now <em>that's </em>doing your best.
What do you need help in Spanish?