Well, it's fiction, for starters.
And it's...well, it's pretty sexist in much of it, and some abuse and rape victims may likely find it triggering.
It was controversial at the time, primarily because erotic romance novels still were: it was published in the early fifties. As well, it does detail some things that are pretty violent in an erotic context, so at the time -- especially with a once-anonymous author -- that was pretty outre, and obscenity charghes were brought, as was often the case with erotic work at the time. In this day and age, the language would likely not be considered porn by many, given it's pretty tame. Henry Miller was more explicit, for instance. I don;t know why, if your library has it, you couldn't check out a copy if you liked.
(Apparently Reage -- whose real name was Dominique Aury -- wrote the story for her married lover, worried he'd leave her for a still-younger mistress, as a way of saying she'd do anything to not be left by him. Make of that what you will.)
But ultimately, I'm not sure it's a need-read per your ACTUAL life, because again, it is basically a romance novel, so it being a tool to understand yourself wouldn't be all that different from saying a Harlequin romance was a way for them to understand themselves sexually. If you're looking for help in that regard, nonfiction is generally a better bet.