Potty training is hard


So my mom had my daughter Friday night to Monday afternoon (today). We had a big snowstorm and she couldn't get home. Anyway. My mom used this time to start potty training her. She is 2 years 4 months. Ive been having a really, really hard time with potty training.. which is why it hasn't already been done. My mom says she was doing amazing.. going to the potty all by herself and everything. She is however afraid to poop on the potty. So she hasn't pooped in 2 days. She is screaming because she's in pain and won't sit down anywhere, not even on the potty. She is now peeing all over the house and refusing to use her potty with me, SCREAMING at the top of her lungs.

I dont know if I should put a diaper on her so she can poop?? I feel like if I do that I'm wrecking all the "progress" my mom has apparently made with her. My mom has been shaming me like crazy because she isn't trained yet and it makes me feel horrible