She might have trauma from the thing before, but people go through various degrees of what she is doing to herself for all kinds of reasons. People aren't into their partner but fake it anyhow, people get performance anxiety, people have self-loathing issues or hate their own bodies.
It's actually kind of mundane to the point I can't sympathise or pity her, especially with the way she treats Miwa in her inner monologues >_> She's got some kind of weird superiority thing going on too.