Ouch, You moved from Boundless to a Lawyer who also seemed clueless.
https://travel.state.gov/content/travel/en/international-travel/while-abroad/divorce-abroad.html#:~:text=Will a foreign divorce be,be heard within these proceedings.
Will a foreign divorce be recognized in the United States?
A foreign judgment of divorce generally is recognized in a state in the United States on the basis of legal reciprocity where both parties had notice of the divorce proceeding and an opportunity to be heard within these proceedings. Marriage and divorce generally are considered matters reserved to the states rather than to the federal government.
Specific questions regarding the validity of foreign divorces in particular states in the United States should be referred to the office of the Attorney General of the state in question. It may be necessary to retain the services of a private attorney if the office of the state Attorney General does not provide such assistance to private citizens.
I can not tell if your divorce was legal, you certainly imply, suggest there may be issues.
K1 is very rarely a good option, there are some specific circumstance where it might but not here, you could be too married for a K but not married enough for a IR1.
Also you could have looked at the super quick DCF process if speed was of the essence.
The first port of call is to see if that Mexican divorce was valid.