I'm sorry your marriage didn't work out.
Here's the quote:
"
When you sign the affidavit of support, you accept legal responsibility for financially supporting the sponsored immigrant(s), generally until they become U.S. citizens or are credited with 40 quarters of work. Your obligation as a sponsor also ends if you or the individual sponsored dies or if the individual sponsored ceases to be a lawful permanent resident and departs the United States.
Note: Divorce does NOT end the sponsorship obligation.
If an immigrant you sponsored receives any means-tested public benefits, you are responsible for repaying the cost of those benefits to the agency that provided them. If you do not repay the debt, the agency or the immigrant can sue you in court to get the money owed. Any joint sponsors and household members who allowed the sponsor to combine their income with the sponsor’s income to meet the minimum income requirements are also legally responsible for financially supporting the sponsored immigrant. In fact, any joint sponsor and household member is jointly or severally liable with the petitioning sponsor, meaning that the joint sponsor and household member are independently liable for the full extent of the reimbursement obligation and can be sued in court or be asked to pay the money owed, even if the petitioning sponsor is not sued or asked for money."
Source: https://www.uscis.gov/green-card/green-card-processes-and-procedures/affidavit-of-support