Dear How,
I know how this feels.
I had a DDay in 2005. My husband was having a PA with an acquaintance of ours.
About three weeks later, he was diagnosed with prostate cancer.
He had stopped having sex with me for about a year, during which he had this affair (and it turns out (I just found out about 2 years ago) that he was also having sex with a neighbor).
I felt angry, demoralized and hurt over the affair.
And now was faced with his possible demise. The result was that we scrambled to "recover" the marriage, essentially rugsweeping.
The focus shifted to life and death.
He had surgery. He fully recovered. 21 years later, no sign of cancer. A blessing.
But he had subsequent meetups with the neighbor, and an EA beginning in 2019.
This go-round, there is no rug sweeping. It has been the hardest thing I ever did, and I thought the 2005 thing was that "hardest thing".
The good news is that prostate cancer is curable, they do robotic surgery that is very successful, and sexual function can be spared.
My hope is that he is cured, and you both can work through the feelings you both have about this diagnosis.