I have no knowlegable advice as I have yet to experience the time period of someone really close to me on their final stages of life. Sandycay's words most likely describe closest to what you are going through and how you should remember your father.
I am sure this is also awakening some grieving in your husband of his past experience with the passing of a loved one.
Take care and I hope your kids are getting through this ok and with fond memories of their grandfather.
