Can an attorney for the lender seize my only income, which is social security?

If your sole income is social security, it can not be garnished. If you are baking cakes and selling them and putting that income into the same account as the ss funds, you'll likely have to prove what is ss and what is cake money. Keep your ss money separate from any other source is the lesson there. You still owe on the debt, unless you discharge it in a bankruptcy, but they can not garnish the ss money. However, should you win the lottery this weekend, they could come after those funds. If you are being told otherwise, you are dealing with someone who doesn't know, or who perhaps hopes you do not know and will agree to start sending payments. Do not do that. You do not have to.