I think that all of us can relate to being worried about something in school. I’m not sure of the severity of your daughter’s fears, but the fact that she doesn’t want to go to school speaks to this being more serious than with most kids’ fears of testing and homework.
I would suggest getting a tutor to help her alleviate her fears. A tutor can reinforce the material with her and help her prepare for a test so that she faces it with confidence. A tutor could also practice test taking skills and teach her some tricks to reduce anxiety. If a tutor isn’t possible, perhaps have her meet with a teacher regularly just to get some positive reinforcement that she’s on the right track. Knowing that the teacher is ‘on her side’ may help her feel better about going to school. If you find that she’s still struggling, you may need to seek more professional help. I know of some kids who had such high anxiety that they needed to chat with a therapist or counselor to examine the source of their anxiety and fears, and then adopt the tools needed to cope.