You were lucky, all LPR over 18 years of age are to carry it at all times to shows their residency in the US It is considered official evidence of your LPR status
(See Section 264(e) of the Immigration and Nationality Act
Wallet stolen few months ago? , and did you report it to USCIS?
It's required the beneficiary carries green card on them always.
Contact USCIS for what to do next.
File in the US, the K3 is dead. Waste of time with K3
start by reading the guides here on VJ very helpful information.
IR1 / CR1 Spouse Visa Step-by-Step Guide on Filing an I-130 for a US Spouse Visa - US Immigration & Visa Guides - VisaJourney
You have to go to SS office, its just like your driver's license when you have a green card, you cannot renew or even update your home address with Texas DPS online, you have to go there to the office.
I remember around 2008-2010 how Vermont and California processing times for K1's would change daily, sometimes Vermont would get back logged while Cali was processing nearly upon receipt & Vise Versa with Vermont and Cali
Those K1 filers were here within 6 months most times.
Your question should of be posted in the MENA forum,( Middle East North Africa)
Best place to get a reply to your question on this topic then the general IR1-CR1 forums