Unsuccessful for Halls, help please!

Hi guys, just wondering if anyone can help me out
I'm going to be starting at University of Westminster studying Contemporary Media Practice in September, and was hoping to be living at Harrow Halls. (On campus where all my lectures etc will be)
However I've just received an email informing me that I was unsuccessful so don't have a place.
I applied the day my place at Westminster was confirmed so couldn't have done so any earlier, I live 3-4 hours outside of London so obviously can't commute, and come from an extremely low income family.
I also suffer from severe, long-term depression, but I didn't put this on my application as I always fear being discriminated against because of this. However I wonder if I should have, as it states that students with disabilities get first priority? I figure this means physical disabilities, which is of course understandable, but does anyone think it is worth contacting the uni and explaining my situation to them to see if anything can be done?
Any help would be massively appreciated, or anyone with experience in these matters. I've worked myself up into a complete state and am feeling pretty awful right now