Oh man - I cannot even imagine what it would be like to go through diagnosis while pregnant... SOOOOOOOOOO hard!
Do you have family / friends who can care for your baby for a bit? If you're not up for going out... maybe they can take your baby out and about for a while, and you and your spouse can order in something delicious? Maybe watch a movie... Maybe just play cards? Maybe just hang out on the couch?
I remember one of my good days... I had just dropped our son off for an overnight birthday party... and I called my sweetie and asked her what she might like to have for dinner.... She wanted take-out thai. I asked her to call in the order... and I picked it up and brought it home to her. We had a really lovely time eating thai food and then watching some cheesy movie that she picked out. It was a good good evening.
Good luck... It's already hard to be all connected with a new baby. Adding the cancer diagnosis and his experience with his mom and your experience with the treatment - that's a quintuple whammy!
In the end, I think it's the small stuff that helps the most... Just a few hours here and there...