Unfortunately, whoever will be helping you will have to charge you something as well. With that said, you have two options: (1) hire a good lawyer or (2) let the house go. I dealt with many people who were in your situation. The bank tells them to stop paying and then refers their loan to foreclosure. It is your decision from this point on if you want to keep on fighting and spending good money after the bad.
You can have another attorney review your situation to determine if the claims you have against your lender are worth pursuing. However, I agree that you must first decide whether you want to continue investing money to fight the bank with no guarantee that you will obtain your desired result.
By posting on this site or answering/responding to questions does not create an attorney-client relationship and is intended to be an opinion only. My opinion is not intended to be a guarantee or promise of any outcome or result in your matter.
To get a complete answer, you would need to provide more details, such as the terms of your loan modification, did you make payments under the modification, has your Chp 13 plan been approved, are you making payments under that plan now and has your sale been canceled? There are many variables at issue but yes, the whole process of lenders not reviewing borrowers for loan mods until they skip payments have been at issue for many borrowers in the CA court system. You would need to decide if it makes sense to continue to pursue the claims though.