"Their loss was not your fault, Fareeha. "

"They depended on me, and I let them down. It was my fault. "

"You'll train yourself to death if you keep pushing yourself so hard like this. "

"If that's what it takes, then so be it."

I imagine Pharah is someone who thinks hard work is the answer to everything, to the point of believing that she could have worked harder to be able to make up for other people's shortcomings.