I suggest either research extensively and DIY or hire a lawyer.
Boundless or other similar services can often give incorrect advice.
First look: the proof of domicile is very weak, more evidence needs to be developed.
Best to have job lined up, rental if possible, driver's license, bank statements, library card etc.
US taxes filed of course.
Joint sponsor lined up (it may take a while to find one), though it's to do with affidavit of support not domicile.