Adjustment of Status - I-485

I have been through a lot with the uscis after I submitted my AOS applications in 2017. I will give my timeline details.

10/2016: sent package form 485/765/130

11/2016 : rfe for Co sponsor

01/2017: first Ead

05/2017: first interview

06/2017: second interview ( both me n my spouse where drilled for more than 2hrs separately)

07/2017 : NOID for more bonafide marriage evidence ( I submitted evidence before the time frame given)

10/2017: applied for ead renewal

01/2018: uscis home visit, I wasn't at home but met my spouses ( Everything looks good according to them)

04/2018: got ead renewal

 

This is my story, I was married back in my home country and icame into the States in December 2013 on b1b2 visa and planned going back after my visit. Shortly after my visiting in December 2013 I got a message back home that my wife was involved in a ghastly motor accident and she lost her life. We we're married for 3 years with no child and it was so devastating for me that I just can't go back to my home country. I overstayed and met my spouse and we got married 3 years after I lost my first wife. While at the first and second interview the death certificate I gave to the io was questioned and I told him that it was sent from my home country by a relative to me here in the US. Since I was not in my home country when my ex wife passed away and i don't even know what a death certificate look like not until when I needed it to process my papers here.

Now the NOID they sent me yesterday indicates that they investigate the death certificate and they found out it was forged and fraudulent, some places on it they said it does not exist. Now they gave me 30 days to prove them wrong. PLEASE WHAT CAN I DO! I NEED LAWERS ADVISE PLS!