I was referred to SS 15 years ago because school refused to support DS1. Can't believe they're still getting away with this shit. You have nothing to fear OP. SS did a home visit and immediately dismissed school referral as 'malicious' - ie wanting to claim the problem was home and not school.
You need an EHCP to get a different placement. Appeal refusal to assess, appeal contents and placement. Get your own EP, SALT and OT assessments. It seems clear your school will refuse to support and may well block, insane though it sounds it does happen. Don't trust your LA. They do not have your child best interests at heart.
You are your child's best advocate.
DS1 was awarded specialist school placement but it was too late and it failed after 5 terms. He has some qualifications thanks to intervention of SOS!SEN and bespoke package of tutors, SALT, OT, psychotherapist and CAMHS but came to a grinding halt with COVID and social anxiety means he is now practically housebound. I am full time carer on CA.
DS2 had an EHCP and so had bespoke package that funded internet school throughout secondary (but I was unpaid LSA). But he now has 10 GCSEs, A level maths, further maths and physics (Astar, A, A) and has just started Masters engineering degree. There is no way he would have achieved that if he had stayed in 'brick' mainstream.
It was bloody hard work and I had to sacrifice my earning potential and ability to earn pension. But at least you see some reward. The exhaustion and stress from continual battle whilst watching your child deteriorate is soul destroying. Not to mention the personal impact on self esteem and well being of being vilified, blamed, disbelieved etc.