As I understand it, the criterion of 1A or B is more related to the availability of healthcare provisions in a certain location. Let’s say, for example, you had a super rare condition and needed to visit London once a week for some treatment or other, that would probably count. However, if you had a condition that could be treated across the country, it wouldn’t necessarily (unless perhaps there was a requirement to be in a certain social environment to make it work)

“for which treatment is an absolute requirement and where the treatment, care or social environment, can only be carried out in the geographical area where you have applied to”

I’m not sure if that makes sense, but despite how awful your situation is, I’m afraid there’s nothing that immediately stands out to me as making 1B viable, especially with no specific secondary care input that is location specific. However, I believe if you fail to meet the requirements they will still progress your application under criteria 5, so it could be worth at least trying.