I think Ronda mainly just has some very deep seated insecurities that were ingrained into her as a child and all came crashing to the surface when Holly knocked her head off.
She has a mom she has conflicts with, and has always wanted to evolve away from, but Ronda also wanted to live up to her mother's expectations in how she performed. Ronda had a dad she puts on a pedestal who's been dead a long time, and she still blamed herself for a slip of the tongue she made when she was like 8 and he was terminally ill that she's always though might have helped push him to suicide. She has no way of verifying that this isn't true, and also can never take him down from the pedestal. Furthermore her father told her whatever that she'd be the best in the world at something when she's a kid, and that was ingrained in her too. It seems like the only time she's ever felt worthy of her mom, her dad, and also herself was when she was the best in the world at something, preferably with the something not being judo.
Her mom had all these crazy sayings, like "practice doesn't make perfect, perfect practice makes perfect" and "no one has the right to beat you." And because Maria Ann de Mars was herself a world champion judoka, everything she said carried a lot of weight, both with Ronda and with everyone around either of them. Ronda couldn't just simply call bullshit.
She never learned that losing was a part of things, that you can be stronger from a loss, or that learning from your mistakes was a part of growing and sometimes actually the fastest way to learn. All she knew in life is how important it was to win, and if she couldn't win, she was scum, and every bad thought she ever had about herself was true and all her haters were right. Maybe if she'd gone to New Mexico and trained under Greg Jackson, or any number of other high level coaches who understood the mentality of a fighter and the pitfalls that come with it, she might not have turned out this way. But she went with a shithead charlatan instead.
Or maybe I'm just overthinking all this.