My son was also experience that when he was 2.5 yrs old when he made his bed wet (actually just one time only). It was the psycological problem.
If he agree, let him have the diaper when sleeping. Only when his diaper is dry and not VV in midnight, you could ask if he want to have the diaper with him when sleeping. (My son rejected from 3 yr old).
Explain to him many children still have diaper when they are 4 or 5 yrs old. NO need to push if they are not ready.
Just keep talking with him and let them know even his parent also experience this before.
It seems that you son is not ready yet. Maybe you have better try it again later e.g. 6 months later.
I didn't wake my son up because for me, his sleep is more important than the diaper. And I waited until his diaper was dry in the morning. But to be fair, my son sleeps around 8-9 hours only at night. So if your son sleeps longer, it is harder.
We have to wait for the child's bladder to mature, and can hold the water for at least 8 hours, and it takes time.
Then your son is quite mature in thinking, maybe he relates grown up = no diaper.
jk67jk maybe right, sometimes he may not be sleepy enough and just buy time by going to toilet. Or he is really worried about wetting himself during the night.
My son was like yours, he refused when I asked him to wear diaper again.
Have you tried these?
1. tell everybody, especially your son, that wetting the bed is NO big deal, just an accident, the only trouble caused is we have to change the bedsheets. And it is VERY normal to have accidents. (my son wets sometimes, and I try to praise him that he wakes up in time, if only the troussers are wet.)
2. Restrict the frequency to go to toilet, say 2 times only in an hour? Then down to once in 2 hours? He won't have much urine within 2 hours after the last urination. You can teach him about this, and help him to overcome his fear. I think he can understand.
I do admire your son, he is very determined to grow up.