Sorry I clearly got angry remembering what my mum had done and snapped at you. I'm sorry for that
I was diagnosed with autism and adhd in my 30's and my dd was diagnosed 6 months after me. She can make eye contact, isn't fussy about food, can talk and is very clever.
But she also gets really overwhelmed, can't process her feelings or her body signs of hunger tiredness ect, her meltdowns were awful she would really really hurt herself
The process is easier than you think. The fact he's been accepted for an assessment means that half the hard work is already over ( for lots of parents even being accepted for an assessment is a huge battle )
So now, all you really need is for nursery, you, your family members to just tell the asd team what you have all noticed about his behaviour. They will probably meet with him a few times too. And they make it fun for the kids
The assessment for kids isn't anything terrible, they have to read a book, do some imaginative play and somthign else I can't remember. All very stress free and easy
The asd team should offer you a parenting course on having an autistic child,
Life will be a lot easier for him and people will be more understanding and supportive of his behaviours and needs
My DD is so much happier in herself now she knows how her brain works