I actually overtrained 4 years ago by not eating enough and riding hard every time on a commute schedule similar to yours.

It took 6 months of granny rides and skipping gym days to really get back to it. It sucked.

These days, majority of my mileage is zone 2, keeping power under 225. It's hard to do here, but LA river, Kenneth, glenoaks, or up latuna turn around before the hill are all flat enough.

Alternatively, and especially with a baby, rollers would be ideal for easy pedaling.

And 5 hours may not be enough sleep.

See if you can go easy 2 days and hard on only one day for a while.