I've just started a very flexible freelance project and thought 'oh ace, I'll get loads done in evenings and at the weekend'
Hahahahahahahaha
I am so wiped out after spending all day with a demanding 3 yo (I do have a baby too but it's the bigger one who is easily the most effort) I have NO brain space, attention span or energy for anything more than collapsing in front of the TV after an hour or so tidying just to keep very low standards in the house.
I have childcare for 2 (ish) days a week and it's difficult even dedicating that just to work as there is so much else to do to keep on top of in time for the next full on children day.
When you thankfully breathe a sigh of relief tomorrow because it's 8.30pm, DC is in bed and you can settle down to a box set or whatever you do, just think how you would feel if, in fact, you had to rev back up again and put in a 4/5 hr shift.......
Some of the pre-schools near me will take children from 2 and they are usually cheaper than nurseries and more flexible on shorter sessions - perhaps you could look into that?? If you cold get him in somewhere from 9-12, pick up, quick lunch and then a nap at home, you could feasibly do 4/5 ish hours but only pay for morning session for example.