First year is 800k then keep it there for 3 months and never let it drop below 400k at the same time deposit 65k a month for 12 consecutive months before the day you apply for second yearly extension. If you go under the 400k it’s start all over again even by 1 transaction on the same day. If your 65k is delayed by a few days and it runs over into the next month then same scenario.
Remember if you want the yearly extension based on marriage or retirement you MUST have your money in your account 2 months before the date of application
You’ll get the visa no problems. Red flags will be raised to full mast at immigration. Expect to be taken aside and given an interview on arrival. Questions like why you live long time here as tourist, I believe you working here.
As you now state you were married overseas then you will need that marriage certificate certifying. Not sure if you have to do that overseas or if you can do it in Thailand.