Problems with co-sponsor

[Whitelily]

My co-sponsor needs to provide copies of tax-returns. He has already signed the affidavit and the USCIS has recieved it. I recieved a request for Initial Evidence, in which they request his tax-returns, but he is not willing to provide them and actually wants to withdraw from the sponsorship. My partner does not have enough income to be the sponsor, nor is there another person who can be a co-sponsor. I need to send it in before March and if not my application will be denied, says the letter. What do I do?

[Annasttasiaaa]

There is no an alternative option except that find another sponsor!