Sue him for fraud. If someone is attempting to use these documents against you in some way, you'll want to sue for a declaratory action that their claim is not valid. But first let them know that you are claiming that the documents have been forged. That company will be MUCH more likely to let it go if are suing the title company and its vice president. You can even ask that organization to join you as plaintiffs.
When you file bankruptcy, you have to decide whether you will keep your house, or not. If not, then the debt will usually go away too. If you want to keep the house, you will typically have to pay for it.
Best thing to do is get a consultation and let someone look at the paperwork. I don't know why you'd have tax returns going to pay a mortgage. Happy to look at it and figure out what the best route is. It is not necessarily bankruptcy.
You need more than a DBA, which is short for "doing business as", typically indicating that you are just doing business as yourself under another name. If you are going to be in business, you need to establish a business entity that will provide some legal protection. Usually we're talking about an LLC (limited liability company) for a business as you describe. Of course, the details matter, and you ought to talk more specifically with a local attorney before making a final decision.
It sounds like you believe that this lawyer gave you a virus. Have you spoken with him?
The question of "fairness" seems to miss the point. Surely you don't think he gave you a virus on purpose. If your question is whether he's liable, my guess is that you'd have a very difficult time proving that this virus caused the issue. Suing an attorney is no small matter, as you might guess, unless you lawyer up with someone else and you are preparing to fork over a substantial amount of money.
I cannot tell you how many patent applications that I've seen that are prepared by folks who should have at least visited with a patent attorney before filing. Hiring us to do the application is not cheap, but the initial consultation is cheap for the value you are going to get in at least understanding the process. I'm sure that I'm not the only one with an office in Southlake...
I agree with the others...see an attorney with all the documents. You might look at your full financial picture and consider bankruptcy if the rest of your conditions warrant it, but I don't think that escaping a single time share contract will justify a bankruptcy all by itself.