OP, your son sounds exactly like mine - now in Year 1. He's also in an independent mainstream prep school. Last year he was hitting, kicking, even throwing chairs. This year there's barely anything. Things can change and there is hope.
He was NOT spoiled, there WERE (and still are) consistent consequences at home (in reference to PPs in this thread), so please don't blame yourself. My son is actually autistic and has ADHD. Impulse control is harder for him than other kids and he struggles with emotional regulation. He is, however, lovely, sociable, kind, and insanely clever.
Here's what I would do (and did do):
- get hearing checked (for glue ear etc)
- get a blood test (look out for things like low iron, vitamin D, magnesium)
- Ask school to sort out an IEP Nd a behaviour risk assessment if they haven't already.
- SALT assessment
- OT assessment
- EP assessment
- arrange an ASD and ADHD assessment. If you go through Right to Choose it is free (but done through a private company).
- see if your school can offer play therapy / lego therapy
In parallel with this, apply for an EHCP. It might not happen but it takes a long time so get the ball rolling (BTW we did manage to get my son an EHCP. It wasnt easy but we got there - think it took about 6 months altogether).
To warn you, in my experince, all the above can be very costly as in a private school you generally have to pay for any extras like SALT and OT. Apply for DLA. This may help with costs of things like SALT/OT etc. We did get my son's EHCP, so his weekly SALT, OT and ELSA sessions are now covered, but it was very expensive for a while and DLA money made it a fraction easier.
We did all the above last year and it made a huge difference. He's thriving at school (and academically one of the top two in his year group). More importantly, he's happy, and the school are happy with him.
One more bit of advice is arrange as many playdates as your son can reasonably cope with, and get to know the families. This made it much easier for us when my son hit another child as we already had a relationship with the families so they knew we aren't bad parents and that my son is lovely. As far as I know no parents have complained about him - they've been very supportive, tolerant and patient, and I'm really grateful for that. Now things are going so well - for now at least - but knowing that the other families know and like us made it easier when things were going badly.
Hope that helps. Feel free to pm me if I can help any more.
PS acronyms take some getting used to:
OT = Occupational Therapist
SALT = speech and language therapy
EHCP = education, health care plan
ELSA = emotional literacy support
IEP = individual education plan (might be known as ISP - individual support plan)