The Verdict: Need More Info
Thai law only recognises a registered marriage, so this turns on registering yours. Do it at a district office (amphur) in Thailand or a Thai embassy abroad; every marriage route starts from that date.
A ceremony, however public, creates no legal marriage. Until registration there is no spousal visa and no nationality route.
You will usually need an affirmation of freedom to marry from your own embassy, translated and legalised by the Thai Ministry of Foreign Affairs. If you married abroad, have that certificate legalised in Thailand instead.
Registration is not backdated, and the roughly three years the nationality routes look for run from it. Then come back to this quiz.