My question involves collection proceedings in the State of: North Carolina

Hello to all, I really need some legal advice. I entered into a Partnership agreement with my business partner in which I would be the credit investor in the business in return for a percentage of ownership in the business. In our signed agreement by both of us, it is clearly written and understood that I would NOT be personally liable for the repayment of any credit cards or loans borrowed.
My partner made payments to the account for the first 2-3 months, then once the economy downturn started to happen one of his (business partner) financial backers bailed out as a result, the payments on the account (made by him) have stopped for the past 5 months. I've discussed the situation with my business partner and even have proof of our conversations in writing confirming that he is responsible for paying the debts on the credit card accounts. My business partner ensured me that he is in the process of acquiring another financial backer for the business, and once acquired he will be able to pay the debts in full.
However, lately (past 4 months) I have been receiving numerous harassing calls from creditors requesting payment, and one of the creditors is now threatening to pursue a charge-off on my credit report then onto litigation. I did not want to face any legal issues over this matter. My business partner is taking longer than expected in getting the financial backer and insists that he is close to closing on the financial backer.
I would like to know how to legally protect myself in the event that the creditor pursues litigation with me before the financial backer is on board. I still have signed copies of the agreement between me & my business partner stating that I am not personally liable, however the credit card is in my name. I really cannot afford an attorney right now, are there any legal strategies that I can use myself to protect myself? If the creditor pursues litigation and issues a summons, what should be the proper way to respond? Basically, how can I prove to the creditor that I am not liable for the repayment of the debts. Would our written partnership agreement (signed between me & my business partner) as well as our documented conversations where my business partner promises to pay back the debt once the financial backer has been acquired be sufficient in defending my case in the event of the summons? What should I do?
Any prior experience, and good sound legal advice would be greatly appreciated.