@Tracy *********
, There is no "normal single O" visa :/
you already HAVE a Non-O visa, and you have two choices when this one runs out.
Go to a thai consulate in another country and get a new year-long, multi-entry Non-O visa
OR
Go to the immigration office when you have 30 days or less left on your current stamp and apply for a yearly extension from the immigration office.
You apply, it goes under consideration for 30 days, the immigration officers might come for an in home visit, and then you go back and get the year extension stamped into your passport.
At least as a foreign woman married to a thai you don't show proof of 400K baht in funds, (y)
Good Luck