@Dan***
, you are most likely on an extension of stay based on marriage NOT based on supporting children. You do one or the other.
Just an FYI: you also have no parental rights because your child was born out of wedlock meaning 100% of the parental rights was granted to your child's mother. Even marrying her, having your name on the birth certificate and having your child hold a passport from your country doesn't give you the parental rights either in the eyes of thai law.
You'd hafta go thru family court to if you wanted to be recognized as the legal father with parental rights. It's not a big issue to you as long as you're married, but it'll throw you right off the rails if you divorce and haven't done this,