I think the main thing to note is your young one is 4 months old, and that's probably just not the time for hobbies or learning outside of baby caring right now

I think the main thing to note is your young one is 4 months old, and that's probably just not the time for hobbies or learning outside of baby caring right now. I have a 1 year-old now and I remember the time when she was 4 months old. Even right now, we have little free time outside of the 2 hours after she sleeps, before we sleep. This is after 9:30pm and by that time of the day we're so tired that I find it hard to do anything productive outside of some light reading. And on most days, those are also the 2 hours we get to discuss family and household stuff (what things have come up, what things need repairs, etc.) that we don't have time to talk about throughout the day, so actual light reading time is maybe 30 minutes a day, and during the most tired part of my day too so it's not like I can hope to write any code during it. From what I've heard from friends, everyone is saying things get a lot easier when their kids reach 4+ years old, that's when they actually see themselves being able to have time to work on anything outside of work and kids. So overall perhaps the advice is, life is long, and just spend time with the kids in the next 4 years, and you'll have time to learn and code for hobby projects again after that.