Thanks Zoe - so as a sort of an update /question, I have been doing 30 mins nap around 9:45 am 10am, but now he has started fighting sleep at the second nap. I can only get him to sleep again at 2:45 and then he wakes up crying 45 mins or at most an hour later. He is usually very tired by midday, (and so OT after that.) He often tries to sleep in the car when we fetch his brother, but I keep him awake to eat lunch and then try put him down, but no dice till closer to 3pm I am afraid.
Seems counter intuitive to cut the nap even shorter as he was sleeping 2hrs in the am and 1hr in the afternoon. So he has lost that sleep, and he still wakes around 5am.
Still, I agree that the problem is most likely that he is doing "night time" sleep in the morning, so I will continue with trying to cut the morning sleep shorter and perhaps I should try to figure out a way to let him sleep at 12?
Also, the NW is very bad. But he is sick and I am pretty sure now teething too because he made 3 dirty diapers, has a terrible diaper rash, is super unhappy and drooling and biting everything.
Luckily my mum has come for a few days to help!!!