Sorry to hear about your husband’s illness.
When my husband had terminal cancer, he was able to claim attendance allowance through a fast track system on the basis of his illness being terminal. You do have to have your GP or consultant agreeing it’s terminal, which may or may not be easy. Our GP refused to agree that it was terminal, but the consultant thought it was. There is a view that “terminal” means six months to a year, but of course nobody really knows how quickly the illness will progress.
If he is awarded Attendance Allowance, he automatically qualifies for a disabled parking badge, which is extremely useful for the many hospital visits.
Good luck.