My kids are 6 and 2. The only time I have for this is after they are in bed, which is around 9:30 when they're both fully asleep, and I'm usually just ready to sit down and mentally checkout at that point.

I feel motivated all day to go to my office at nights, like I do right now, but I'm so drained after parenting kids all day.

I'm sure you're aware of this having a 6 year old, but once the 3 year old is a bit older you'll be able to do it during the day. I study and do stuff on weekends with my 6 year old while he plays Minecraft on a laptop next to me. And I try to explain how mods work and such. So you're almost there to when you can have some time back to do that stuff during the day.