Four months is really young to sleep independently at bedtime so I wouldn’t beat yourself up if it didn’t work. My DD is 8.5 months and she was a terrible sleeper thanks mostly to some issues with digestion. We’re doing better now but honestly it was only after 4 nights of very intense sleep training (controlled crying), that we started doing better. Before that DD had us in a chokehold - screaming for boob, inconsolable otherwise, every 1.5-2hrs at night. It was hell.
Now, we’ve got the following routine:
wake: 06:30/07:00 - she’ll entertain herself quietly until we get up at 7.
Breakfast: 07:15ish - food first, then breastfeed (she’s been EBF since birth and now we do a mix of spoon-fed and BLW. She eats well after a slow start. fruit & veg, meat, and whole grains. We’re taking it easy on the dairy because she may have an allergy/intolerance, and is currently suffering from constipation ☹️)
Nap 1: 09:30 - she’ll do anywhere between 45 mins to 1.5hrs
snack: after nap, approx. 11:00 - breastmilk. I don’t let her feed for long because I want her to eat.
lunch: 12:00/13:00 - food then milk
nap 2: 14:00/14:30 - I never let her sleep more than 2hrs in any one nap and never after 4pm.
Dinner: 17:00/17:30 - food then milk. Usually dinner takes a while!
Bedtime routine: approx 18:15 - Bath, books, bed.
Sometimes this slips but we aim for sleep by 19:00.
At the moment I’ll wake her to feed at 22:00 and 02:00. Next week we’re moving the second night feed to 03:00 and we’ll do that for a week until ultimately we’ve phased it out completely. Then we’ll start pushing the 10pm feed later in the same way. I’d like her to sleep through the night without a feed by 12 months when I may begin weaning her off the boob. (May go to 18 months if necessary but that’s my limit!)
The best thing we did was break the association between milk and sleep. It means my partner can offer comfort if she wakes. If it’s a bad night and she cries after 7pm, we leave her for five mins before going in. We talk to her and stroke her head, and we might put on white noise and/or offer her dummy, (or pick her up if she’s really upset). Sometimes she wakes with a squawk or two but puts herself back to sleep. She’s like a different baby! Now we know if she’s really crying in the middle of the night it’s because she needs something specific like a nappy change, or she’s ill. Before it was often because she’d wake out of a sleep cycle and couldn’t go back to sleep without using me as a dummy. It was so stressful for her, and for us!
I’d say keep expectations reasonably low and try to be as consistent as you can. If he’s only napping while in motion, try to break that habit by sticking to routine naps in the cot for a bit. It’s hard but he will get there. Good luck!