You can check the court file to see if it reflects service upon you. You can obtain, for a modest fee (usually about $1 per page) a copy of any documents you want out of the court file. The court record will also reflect whether you are named, individually, as an additional party or sole proprietor of the named business.

You can try to negotiate a payoff with the creditor, or with the law firm representing the creditor. I can't promise you what sort of success you might have.

Given your debt load, I suggest consulting a bankruptcy lawyer.