Autism and Housing

I was wondering if anyone would be able to give me some advice. I currently rent my home from a housing association, we live in a two bedroom house (myself, partner, teenage daughter and four year old son.) My son has Autism, Global Development Delay, Sensory Processing Disorder and Hypermobility. Our house is far from ideal and the older my son gets, the more challenges we face. I am having a battle to get our local council to understand and recognise that my sons medical conditions are getting worse due to overcrowding. We are back on the housing list but in a low banding as we have gained points for being overcrowded but nothing as far as my son is concerned. Our OT and his early years special education teacher have both written into the council to explain his condition but its almost just dismissed. He is non verbal, doesn't understand many instructions (cant dress himself, still in nappies etc) He makes a lot of noise day and night and my poor daughter (who is sitting her GCSEs) is also now struggling. If we did get his condition recognised and how much being in a two bed is affecting his development we would be considered to have compound needs, meaning we would higher up the list and be able to be more successful when the right property is available. I don't want to seem ungrateful as I actually love our home (we have been here for 11 years) but it just doesn't work now we have a child with complex needs. He is in the process of having his EHC plan created and he also has a 1to1 at preschool. Any advice would mean the world as I know the best way to move forward is to stay positive and not get to overwhelmed. Thank you for taking the time to read about my family.