Remember that although death is unpleasant and your reaction to it is very unpleasant it is still a panic reaction and it is this reaction you want to deal with with The CBT just like any other Panic reaction. CBT will fix it. You will still grieve but there is a difference between grieving and accepting and panicking at the thought. You can learn to accept it as a fact with out going into a panic state.
It is normal to feel relief when your husband gives in because people with panic and anxiety need to feel in control. Trust me though no one has ever died from a panic attack, even though you feel like you may. If you stay in the situation long enough the panic will go away. While this is happening lay down and take deep breaths or talk to your husband.
On the topic of death it is tough, it comes when you least expect it and takes people we love dearly. I am sorry to hear about your loss. As an ex firefighter I have seen it take both young and old, what gave me comfort was and this may sound morbid but reading about what happens at the time of death, instead of going into it hear I will let you decide if reading about that is something you want, just google it there is a lot of info out there.
On the other hand the human body can endure a lot and I mean a lot before it gives up the fight there are a lot of tails of survival out there and I have seen it first hand as well.
Every day we get is a gift and thats why its called the present. Love the ones that are close to you and challenge yourself everyday.
This week created some major setbacks for me as I learned of a younger relative dying. After hearing the story of how suddenly she died at only 21, I was offset the entire week (as many people would be) but on Saturday night I had a major panic attack (which I have not had like that for over a year). I was sure that I was going to die just like she did and had my jacket on, shoes on and was in the truck ready to drive to the hospital to seek help. After somewhat calming down with the help of my husband I only felt depressed, guilty and scared. I hate putting him through that but when he continues to try and help me by telling me it is just anxiety and to breathe I only fight him more on it telling him I need to go (to the hospital). Its almost as though when he gives in that I start to calm down. My problem with death is not that I can't accept that it is a part of life because believe me I know all to well that it is a part of life. Its that I just cannot stomach and continue to worry about when me or the ones I love will be gone. Once upon a time I did not think about these things. I want to be a person that does not worry this stuff as much as I do.