Thank you for your follow up.
Unfortunately, if you did sign the Affidavit of Support for your wife, you would be held legally responsible to pay 125% of the federal poverty level of spousal support
for your wife in case of divorce if she is unable to find employment, until your wife becomes a US citizen or works for 10 years and earns 40 qualifying quarter retirement credits.
Also, if your wife becomes public charge and received government benefits, before becoming a US citizen or earning 40 credits, the government can and in most cases does go after the sponsor for any money paid to the sponsored alien spouse.
You can read more about it at the link below, which has all the specific details and updates about your liability under the I-864 to your spouse or any other alien you have sponsored:
I would strongly urge you to consult with a local divorce attorney who has handled similar cases, before proceeding with your divorce, as in most cases it is simply better to wait for the alien spouse to become a US citizen, in the situation similar to yours.
I wish you the best of luck!