3 year old son suddenly won’t sleep alone and waking in the night - please help

[Soph0208]

Hi.

My son is 3 next month and for some reason three weeks ago has completely changed his sleeping habits.
Since he was born he’s been a brilliant sleeper, always slept through, and we’ve always been firm with leaving him to cry eTc when needed.
2 months ago we moved him to a bed, and he was brilliant, didn’t get out, came in our room early but can live with that!
Then approx three weeks ago suddenly one night he wouldn’t let me leave at bedtime. Insisted on me holding his hand till he was asleep. We have managed to get further away over time and now my hubby sits in his doorway and he’s asleep in 10 mins... problem is he’s now started waking in the night. He comes into us, I take him straight back to bed but he won’t go to sleep without me sitting there. Sometimes doesn’t go back at all. If he does go back off he’s up to start the day at 5am. We are so tired and just can’t understand it. Why has he suddenly started doing it?
A few things have been going on, we have started potty training and he went for a couple of nursery induction visits which he loved! I just can’t see what I can do. Please help!!!

No idea if this is relevant but the same happened with my DS when he was 3. He had always been a brilliant sleeper. I think the reason was that he started to get scary dreams and was frightened to go back to sleep. It happened in waves, he would not sleep well for a few weeks, then be ok for a bit, then the same again. He couldn’t tell me about it to start with, not verbal enough, but did just before he was four. Anyway, he is now 15 and still a brilliant sleeper, he continued to get the odd bad dream and need extra reassurance going to sleep & in the night throughout primary several times a year, & into secondary school too. But now I come to think of it, I think it’s stopped, he hasn’t mentioned it for ages. But I think his imagination had got to the point where it could scare him. Lots of cuddles, no scary bedtime stories or telly (he was always scared by stories and I used to read ones too him that were for much younger children because of this), and just lots of reassurance if he had a bad dream. Good luck working out what it is, could be nothing to do with dreams at all.