@Annette ******
I'm going to let Tod Daniels chime in, but from your consulate website, I found this document:
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1.pdf
The biggest problem is, do you have 200K THB in your bank account for the last 6 months, and a letter of employment?
I'm guessing the second part would be no, because you're retired. Maybe someone else can chime in if that's going to be a problem.