Hi Mrs. B.
I think it is great that you are so understanding of your husband's condition. It is very difficult for those who do not experience panic attacks to understand them and he will need all the support he can get. Don't worry, his frustration at you will subside when he becomes more educated about panic attacks. So hang in there. I would suggest that both of you read some books on anxiety. It will help your husband understand what is happening to him, and will also help you, help him during this difficult time. Two books I highly recommend are Hope and Help for your Nerves and Peace from Nervous Suffering, both by Clair Weekes. (Boy, this woman was so ahead of her time). These books not only describe the symptoms of panic, but also teach you coping mechanisms.
Medication is also an option that your husband may want to discuss with his doctor (When having panic attacks, no one needs to feel like a hero because they don't take meds). Anti-anxiety meds or anti-depressants may help him through in the beginning until he learns how to control his symptoms. Panic attacks are a very scary thing, but remember, they cannot hurt you, even if your mind tells you different.
Best of luck to both of you.
