My coworker had a full hysterectomy in her late 30s for the same reason and she’s described it as basically a living hell for about a year. Just a complete nightmare where she felt like her body completely turned on her and she had no control over anything it was doing - hearing about it made my attitude about keeping my ovaries much more enthusiastic. BUT she was pretty much fully through menopause after that year, so the good news is that your wife’s situation is likely pretty temporary. The bad news is that a year can feel like much longer when things aren’t going well, and I’m guessing she can’t do any hormone replacement to ease her symptoms because of the cancer risk. I did keep my ovaries and I’m still having some hormonal nonsense (pseudo hot flashes are not making me real optimistic about the real thing, let me tell you), so I can only imagine how much that sucks.
The thing is, you’re probably not actually doing anything wrong, it’s just a total tsunami of fuckery in her body atm that’s making her feel that way. I would suggest marriage counseling, because it’s possible that a neutral third party can help your wife see that, even though she’s not totally in control of her body or feelings right now, she still doesn’t get to make you feel like shit and she might end up destroying a relationship she still wants once she’s past this stage. There’s no easy solution, though, it’s just everyone putting their heads down and pushing through it, unfortunately.
She’s a rat, the fat is just making her head look shorter than it is.
(Also, for anyone concerned about abuse, she has a disorder that causes her to get fatty tissue deposits, she’s not obese.)