I don't believe you need a divorce certificate from a district office as you had a judgement in court. That is your legal divorce. The Amphur divorce certificate is what you get if you get an administrative, consensual divorce at a district office. It's either one or the other, not both. I got one last week actually (mutual concent divorce sections 1514 & 1515 Chapter VI of the Thai divorce law)
Best to talk to a lawyer. If you're in Pattaya, I can put you onto a competent family lawyer who speaks English better than most expats. If you're not in Pattaya, he has agents in Bangkok to quickly organise any paper work you might require, such as certifcation of an English translation of your divorce judgement by the MFA.
If you reported the marriage in your home country, you may or may not be legally divorced. Some countries require marriage and divorce to be reported, some don't.
There's a lot of good information here to get you up to speed:
https://www.the-social-lawyers-company.com/how-to-divorce-in-Thailand.html