potty issue *help*

my 3yr old daughter has been using the potty sense she was a year and half almost two. And the last 3 days she has been going in her undies like everytime i would say shes has used the bathroom maybe twice at of the 3 days and not only that she has been talking back to me like saying  " no i dont want to" and then she will throw stuff on the floor and i would say why did you throw it on the ground she says cause she is mad and then cries cause she wants it but wants me to get it and will cry for about 5 mins and sees that im not going to so she will get it
and thats not normal for her i am really worried cause i dont want to have to put her back in diapers all over again
please please someone help i took her to the doctor today and she said she will pass it by but i cant take it any longer i cant stand to wash anymore of her pee clothes