Refused correct amount of housing benefit URGENT

Can anyone offer advice/a legal opinion please? My (owned/mortgaged) home is being sold due to divorce. I have a shared equity deal with Heylo (not social housing) and will have to pay rent on the proportion of my new home that I do not own. I'm in receipt of DLA at the higher rate for care and mobility (as well as being in the ESA Support Group) so am entitled to a 2 bedroomed property in order to accommodate, sporadically, someone to help or be with me overnight. To my horror, having found a 2 bed property and being close to exchage of contracts, Adur DC say they will only pay housing benefit for a one bedroomed property unless I can provide them with proof that I engage the services of a professional nursing agency overnight on a reguar basis. Obviously, at £25+ per hour, doing so is way beyond my means. I rely upon my son, daughter in law and friends (who all have their own homes) to stay when required but Adur says it will not accept this. Surely this cannot be correct when, according to every other body including DWP, I am entitled by law to 2 bedrooms. Benefit for a one bedroomed property will not nearly cover my rent, will reduce my benefit income and therefore the amount Heylo will "lend". That means my Agreement in Principal will be null and I shan't be able to afford the new property. I'm scraping the barrel as it is so please dont suggest I find something cheaper. I'm aware, of course, of my right to ask them to reconsider and of appealing to a Tribunal (6-8 months). Thoughts please?