No, I don't think it's a phase. It is not normal for a 5 y.o. to behave like this. If she is having tantrums and you can't calm her down, it's time for a visit to the doctor. Again, this is not normal.
Her behavior could be due to a neurological issue, environmenetal issues, psychological issues but you need to find out what is going on with her.
Good luck, you've got your hands full and I hope you find help.