You'll need to read your mortgage paperwork to see what the default remedy is. CA allows both judicial and non-judicial foreclosures, which means that your mortgage will tell you whether or not they will come after you for the deficiency balance.
This is completely separate from your divorce. You signed a loan agreement, and it is enforceable, regardless of what you and your husband decide in regards to a divorce.
You won't have 15 years of ruined credit. BK only stays on your credit report for 10 years. A deficiency judgment can stay there for a long time, though, if not paid.

