@jeffreyhoward Welcome to Mayo Clinic Connect, I am glad you found us and have posed this quandary you are in.
I hope that you will have read the response posted by @valentinaz, by now. It has some very simple truths in those words. I am an active cancer patient, going in to my 8th round of chemo.

The millstone of a cancer diagnosis, then treatments can weigh so heavily on the patient. Knowing your spouse/partner is concerned for how to offer support is a big deal, as that support can be defined in so many levels. Daily tasks, cooking up tempting meals when nothing seems appealing, being the chauffeur for errands and appointments, running interference for well-meaning family and friends when you feel like curling up on the couch. All those, to me, spell "support", and there are many more examples, no doubt. You haven't mentioned what form of cancer your wife has, and if she has communicated what she would like from you. This is a journey that you take together. Are you open to share a bit more with me, and we can help you understand your all-inportant role?
Ginger