What to do if we were discharged in bankruptcy 5 years ago and a piece of real estate was included but now the bank is coming after us for the defaulted loan?

Ideally, you need to have your bankruptcy attorney send the creditor copies of the bankruptcy paperwork.  Based on what you describe, they should be barred from their current collection efforts-- but you do need to take steps to notify them.  The best person to help you is your bankruptcy attorney.  If you cannot get your bankruptcy attorney on board before your hearing, make sure that you appear with the paperwork and request a continuance with the court until you can find an attorney to help you asset the defenses listed in your question, namely that this debt has already been discharged.

You also mention this is set for a "default hearing".  If you have not already filed a general answer, then you need to do so to prevent a default judgment from being entered against you.  Copy the heading of the petition they filed, but change the title to "general answer" and below it write a statement to the effect that you are entering a general denial to all of the plaintiff's allegations.  This isn't the best answer, but it's a basic answer to stay off a default judgment until you can find an attorney to file a more specific answer with your defenses properly listed-- which you really need to do based on the facts that you describe.