Oh Lynne, I think you are coping quite well considering that you were told not to worry and then the opposite!
But the crude truth is that all of us can get cancer anytime even if we have been cleared from a previous one, there's no guarantee another won't strike again, it's all about family history, environmental risks and probabilities, really.
If you take the advice given from coldethyl, Teresa, marras, who are dealing with cancer, then you shall have a great advantage to win the battle. The war is another matter, we all know that all we can do is fight our battles, but to win the war is just out of our hands, and that applies to everything in life.
Maybe your husband is avoiding the issue because he really loves you and it's hard to bear seeing you suffering. It's a process and it takes time, patience, clear thinking (which is impossible now) and much, much love for himself as well.
Anyway, I feel you will get out of this stronger and ready to live each second with less fear, worry and distress. That's my feeling and sincere wish.