@Akkhan94
You have posted this on the worst part of mumsnet for this kind of thing. Take a look through the topics on Special Needs and you'll find more support. Kids with Agenesis of the Corpus Callosum can sometimes present like neurodivergent kids, and there will be parents on the Special Needs area that understand the particular daily challenges and the habits and routines you get into because needs must.
There's so much more than housing here.
Have you applied for child DLA? This is Disability Living Allowance and children with any disability are entitled to it if they have care needs that exceed what is "normal" for a healthy and well child of the same age. That includes supporting challenging emotions or behaviour. Like everything health, the form is quite geared up toward physical disability so you have to take time and care to complete it where the challenges are emotional, behavioural or developmental.
Your child is going to school soon -you would really benefit from being involved in a formal process that acknowledges your child's needs and rights to accomodation/adaptations. EHCP is the usual process in England and Wales.
Your child having a clear disability, on an EHCP and receiving DLA would usually be enough (along with a letter from GP/Paeds/Nursery/School outlining challenges) to ensure they have appropriate consideration around priority for housing. You do have to be very clear about the specific housing needs and why...as well as why the medical history/disability is important.
Unfortunately, nowhere in the UK can you expect that authorities and professionals will bring this information to you. For every parent with a child with special needs, it's an uphill struggle and you have to be prepared to fight for and advocate for your child's needs. Sometimes you do find great people around who can help -a health visitor, a welfare rights officer at the Citizens Advice Bureau for example.
https://www.mumsnet.com/talk/special_needs