I haven't read the whole thread, but I stared this with dd & want to tell you my experience.
I have just done this with dd, aged 3.3. 2 days before you, actually! Exactly the same, given to santa. Santa left her a toy, so each time she mentioned it we would mention the toy & she would be happy (er)
Her naps have gone too, but I insist she has at least 30 mins quiet timne in her room, reading or playing quietly. Losing the nap has helped us tho, as it means that she is more tired at night & therefore likely to fall asleep quicker.
At night time I just went with it. Kept going in to reassure her, reading stories, chatting, lying with her, singing quitely. Anything to distract.
Wed/Thurs/Fri night were a nighmare! Friday I was sitting by her bed crying from it all & wanting, so bad to give her her dummy back. Then Saturday it just happened! Asleep in 20 minutes! That is how it has been since. I have to say that on saturday I decided I couldn't keep going into her as she would just replace the dummy with me. So I left her to whine a bit.
I know it is very hard & stressful. But he has to train himself to go to sleep without it & you can only help him.
Losing your temper will not help, as I am sure you know...I lost mine too...mainly at dh as he did bugger all to help & just said give her her dummy back....