@Hea****
it is highly unlikely that you're gonna be able to pull off getting the affidavit of freedom to marry, getting it translated, getting it certified by the MFA and then getting an amphur to register the marriage so can get to the immigration office and apply for a marriage extension before your ED visa extension runs out. :/
Even if the embassy accepted your emergency request (I'm not even gonna ponder how getting an affidavit to marry qualifies as an emergency :O) I don't think you can pull it off in the short time you have.
That's why I suggested a way to "buy you time" by getting documentation from your school stating you stop studying on the 15th of Jan, go to the immigration office the week before that, cancel the ED extension, (they will give you a new stamp saying you can stay until the 15th) and then immediately apply for a 60 day unable to travel due to covid extension.
That buys you two months more time from the 15th of Jan.
Then you don't have a gun to your head time wise and can take the time to get everything done step by step and after that go back to immigrations and apply for the yearly extension based on marriage to a thai once you have all the stuff you need.
I think you have as much info as the group is likely to be able to provide you. Good luck in your endeavor. :) Take care, stay safe.