Thanks for sharing. I did it on the App "Inmigra USA" the community of Immigrants in the United States. inmigrausa.com There are immigration lawyers and free collaborators. Stay up to date on news of interest to the Latino community. Search Inmigrate USA. I chose the Florida community, it looks like they are starting now, so I recommend you choose Florida. Busca inmigra USA el app del inmigrante, de verdad es muy buena tambien. Thanks!!!

3 years after you received your green card, not 3 years from the date when you got married

You can apply 90 days before it will be 3 years since you received your green card. You can also check on USCIS website for eligibility, it gives you the exact date you can apply for citizenship based on questions you answer.