@loislovesstewie, I'm so sorry to read what you're going through x
I have experience of a very young child showing signs from aged 2 gender dysmorphia and he now lives as a little girl. Prior to changing names, he (now she) was extremely obsessive over her sisters clothes and toys and showing no signs of interest in any stereotypical "boy" toys. Wanted to wear dresses and play barbie and parents took her to a therapist who said to let her live as she wished, as her behaviour was frankly horrific and then consider hormones etc when the time comes. Since this child has lived as she, not he, her life has improved massively.
But her parents fear of hormones or surgery are terrifying them. So they're basically doing everything they can to ensure their child is happy, using her chosen name and pronouns etc, but are so scared within the next 10 years their child will do irreparable damage to their body or will go through puberty and it crush her mentally. Its so sad to watch.
Now, I've a transwoman friend who has full surgery etc and if I'm honest, she seems to massively regret it and was probably just a gay man who felt ashamed. Her life is lonely, she lives as a woman but seems to have no joy from the things she presumed being a woman would bring. I think if she could go back, she would. But she can't. (I do know I sound stereotypical saying things here, but I mean she has none of the enjoyment my friends trans little girl has in living as a female)
I really do believe gender dysmorphia is a real thing. I don't for a minute think it's as widespread as people believe. I think it's honestly rare as rocking horse shit and this is almost the new vegainsm that people went hardcore for years ago or crystals etc, but just far more radical and dangerous.
I see the improvements in the child's behaviour now they live as a girl but no improvement in my friend who now lives as a woman, if anything she's more isolated than before and hates leaving the house as she feels like people are staring at her. Sometimes, they are.
I can't imagine the awful place mentally a child wanting to permanently change their body must be for a parent. Especially if it's seems to have no benefit to how they live or even give them much joy.
I just hope things work out for you and anything long term he does goes smoothly.