As a USC spouse, you did not file an application, you only filed an I-130 petition for an alien relative and it is possible that you also filed an I-864, the withdrawal of the I-130 and/or denial or the I-485 will negate the affidavit of support as the support requirements only kick in when the sponsored alien obtains an Immigrant Visa and lawful entry after inspection and admission at a port-of-entry OR adjustment of status (approval of I-485)which is the same as lawful entry after inspection and admission. If you filed an I-130 concurrently with the I-485, it is likely still unadjudicated and as such you can simplly withdraw it. If the alien spouse has departed, if he had advance parole, mention that fact, so it may be revoked/cancelled. If the alien spouse did not have advance parole (I-512) in hand then the depture is viewed as abandonment of the I-485 and MUST be denied as abandoned, with no appeal or motion allowed.
Sorry that things did not work out for you.