Or about forced marriages. Here she was, perfectly happy and willing to live a life of solitude, and now she has been married off and has to smile to her husband every day (not even lest she be beaten, but because her body isn't free not to smile ever again).
Timo Saloniemi
You don't get it. "Metamorphosis" is not a dark and gritty episode. It's not supposed to be "Arena" or "Balance of Terror." If you shoehorn this story into a simplistic, "one Star Trek fits all" template, you destroy it.
Even worse: if you superimpose a harsh, movement-feminist template over an episode that is NOT about gender issues, you miss the point entirely. Men end up lonely, too; Hedford just happens to be a woman.
Nancy Hedford is not "perfectly happy," or any other kind of happy, going into these events. The script makes a point of that. Furthermore, after the merger, Nancy still has agency and volition within her new identity. Prior-Nancy is as much a part of the new being as Prior-Companion is. The new person is something more than she was before, and she's happy.