I know bankruptcy sometimes is the only way out of a financial crisis, but I strongly urge you to pursue it only as a last resort. I'm not a lawyer, of course, but I do know that bankruptcy can affect your life for years to come.
Is it immoral to declare bankruptcy? Some have argued that it is, since someone is going to have to pay for the debt you incurred. However, I find nothing in the Bible that explicitly forbids bankruptcy, as it is provided for in our legal system (unless the motive is to cheat someone who has lent money to us). The Old Testament actually provided for the cancellation of debts every seven years among the ancient Israelites (see Deuteronomy 15:3).
At the same time, let me urge you to explore every alternative you can. For example, have you considered renting your first house? The rent might completely cover your mortgage payment -- and even if it doesn't, it still could help you financially. A financial counselor may have other suggestions for you to consider. The Bible says, "Plans fail for lack of counsel, but with many advisers they succeed" (Proverbs 15:22).
The most important advice I can give you, however, is to seek God's wisdom, and to trust this whole matter into His hands. He knows what is best, and He can be trusted.