Sorry for the late reply; I don't log on very often :p
Content warnings for this comment: spoilers, mentions of: SA, injury, trauma, amnesia, vomiting, self-harm
I agree with your assumption! It's very heavily implied that Hazel has trauma from multiple instances of past SA and injury. The content warnings also likely confirm this. When I was watching my friend play, I took note of the line about how the Duke would often pull Hazel's hair out, implying more constant abuse. I also like how Mary offers to trim her hair, sort of as a sign of moving on from her trauma. The comfort makes things hurt more as the plot progresses imo. (side-note, I really like the character designs cinnamew's games have! they're so thought-out and themed really elegantly!)
Furthermore, Hazel's amnesic trauma response and overall fawning characterize her as someone trying to internalize her interpersonal trauma. We also see her making an effort to avoid her traumas and live normally in spite of them, something the plot repeatedly forces her to confront.
After the scene where Hazel's traumas resurface, we see her vomit as her memory comes back; vomiting is a response to extreme disgust, and is not uncommon among those facing the disgust of sexual trauma and abuse. In terms of what Hazel does during the time she loses her memory, it's ambiguous whether she vomits involuntarily or not. The vomiting can be self-inflicted as a way to cope, akin to how self-harm is used to cope, or it can be a response to the disgust itself.