TG.
I am in a similar position to you. I can understand how you feel. The folks on here already know that my partner of 30 years was diagnosed with stage 4 cancer the week before Christmas. We don't know how long he has left but it's months not years.
I haven't ran since then either. I can't, I don't feel like it and everything aches. I can understand how you feel.
My mother was diagnosed with breast cancer when I was 10. She died when I was 18. There wasn't any support for us at the time and we fell apart as a family.
No one under estimates what you are going through and it is individual for each person. Do you have a MacMillan nurse asigned to you? When my mother was ill it was the feeling of isolation, of having to cope alone, for me, I tried to be my mother and do all the things that she couldn't do. Silly things like being Father Christmas and the Easter Bunny and the Tooth fairy. (even though we were too old we needed the magic). It's not just the everyday stuff like washing and cleaning and getting on with life that becomes so much harder, it's the dreaming. Sometimes the furthest you can see is today and all you have energy for is to keep putting one foot in front of the other. There's no pause or reverse button. You can't unwind or go back to a better time and bypass all the shit.
I don't know anything about your wifes condition TG. There is a good survival rate for breast cancer. I know that the journey is not always easy but I hope that for you and your family the destination is one that you would choose and that your world settles back on its axis.