We're lucky in that (so far) our 5 month old has been a happy, healthy baby. And my wife is very understanding of my need to ride (physically and mentally).

A few things that we did/do that might help:

Make sure she gets time to do something she wants (exercise, read, take a bath, go for coffee with friends) even if it's only 30 mins. You can ride the trainer for 30 mins and get a workout done.

If cycling is your priority then drop EVERYTHING else that you do/did. You don't have time for multiple hobbies, so pick one.

Agree with your wife that if she needs you to stay home you will. Even if you are fully kitted-up and at the door headed to your first group ride in 3 months, if she says "please stay home" then you gladly do (no b1tching). This helped my wife realize that I was committed and there if she needed me.

Fit rides in when you can. Have the bike setup and clothes ready so that you can jump on at short notice. You're not likely to be following a structured training plan for a while. So ride WHENEVER you can.

Lastly, all kids go through spells that are easier or harder for them and for you. You already know that the rewards outweigh the downside. Just try to keep that at the front of your mind.