You need support at a time like this so accept any support you are offered.
Sometimes something like this can be just as traumatic, if not more so, for the loved ones as the patient.
Indeed working in Oncology I often find relatives impossible to deal with and yet, conversely, the patients can appear awash with calm.
I hope your husband makes a full and speedy recovery.
Finally, give yourself a huge pat on the back for going with your instinct - you undoubtedly gave him more of a fighting chance.