no one has even thought about a medical condition! (well unless I cross post with someone

)
There could be something very seriously, medically, wrong with her!
Your wife needs to go see a doctor
(*) to make sure that her endocrine system is working properly. She could be hypo or hyper thyroidic, she could have low testosterone (Yes, Women can have a low testosterone level), her progesterone could be off… oh my, just so many things that can go wrong with this system.
(*) She needs to see an Endocrinologist - as much as we love our general practitioner, we take our children to pediatrician, we see a dentist for our teeth, and my Wife and girls see an OB/GYN for well, the female parts (to keep this G-Rated

), and we see an professional that has training dealing with the endocrine system as it is like a Rubik-Cube, you can solve it and you can really mess things up!
In conjunction with the endocrine system evaluation, she needs to be seen by a mental health professional to determine if she is suffering from any sort of depression or other such condition.
Finally, I would encourage some honest marriage counseling. Contact the diocese where you live and get a list of councilors that follow good Catholic doctrine - you don’t need one of these “New Age” lets add a third party to the mix to spice things up type
Personal experience:
-When my wife and I were first married, well, Rabbits were jealous

-Then several years down the road, things dropped off… very frustrating.
Also my wife simply didn’t seem to have any energy for anything really.
-She went in for an unrelated issue, sinus infection if I remember correctly, and the doctor looking at her, along with the lack of “energy” and thought something else was up, and ordered a simple blood test for TSH/T3/T4 levels - these are the thyroid hormones.
-This test came back as abnormal for all of these…
-It was a long time getting things under control and the GP wasn’t able to get a handle on so we were sent to an Endocrinologist. During this time, while the Endocrinologist worked their magic, my wife has been under treatment for depression. Part of it is caused by the hypothyroid condition and part is that she is simply depressed.
- Now I won’t (can’t) tell you things are back to where they were some 20+ years ago. Frankly, we now have 4 children (something the Endocrinologist helped us with by treating the HT condition and our OB/GYN has training from Pope Paul VI institute to help support) and we’re just simply a little older; however, she’s at least interested in the marital act enough that we have to be open to new children and we use NFP.
- All of this, because, a GP, saw my wife for a series of sinus infections. In the 20/20 of hindsight, we should have seen this, as all of the symptoms were there, and have had her tested and treatment started years if not a decade sooner - we suffered when we didn’t need to.
- BTW: Don’t expect an overnight cure. It has taken us four doctors and 10 years to get as far as we are… and we had to learn a lot about how the endocrine system worked, especially how the thyroid works, and quite often had to insist on a course of treatment. Thank God for the OB/GYN my wife sees now as he’s on top of the situation and if my wife says she isn’t feeling right, the blood tests are ordered, the meds adjusted and within a few weeks things get back to “normal.” 10 years of up and down, 4 doctors, I pray you don’t have to go thru that too.

So by all means
Pray
Offer it up
etc…
As our suffering can be used by God for the good of His creation
However, get good medical and professional help too – the good Lord gave us Doctors to help take care of our bodies and our mental health!
THANK YOU. Why do we assume that his wife is just being cruel/denying her role in marriage instead of wondering if there might be something wrong?