Ds is 3.6 and disabled - his crappy sleep seems to be part of the syndrome he is suspected to have.
He is on melatonin, which helps get him to sleep (he used to up until 12 at night) but if he awakes in the night he can often be up for hours - on Monday night he woke at 10pm and was up all night, he was hysterical whenever dh tried to take over to give me a break, and because we were at friends we didn't want him to wake up the whole house, so I had no sleep at all for the whole night. He wakes every day at around 4 am, and is often up in the night with reflux or because he has a bad chest or because he is choking on his own drool.
It is exhausting, but it is what it is, and dh and I just make sure we try and take it in turns to get rest at the weekends, and give each other a lie in. If the girls (we have dds aged 6 and 7) wake up, one of us will climb into bed with them, whilst the other deals with ds.
I drink a lot of coffee and eat too much chocolate, but on the whole it is ok. If ds has an all nighter or is in hospital or if i am ill, then it feels like it is going to tip me over the edge, but so far I am still clinging on!
I really hope your and ds's chest gets better, it is horrible and I always have sympathy for friends that have sleepless nights, I would hate to be one of those parents who act like, 'you'll never know what tiredness is!' because it is always hard to deal with, whatever the circumstances.
for you.