Just get a one year statement for 2024 from Bangkok, it will show all of your deposits for the year that were transferred in from the UK, add them up and just give them that number
just take your wife with you to the tax office, they will do all the paperwork for you online. No charge for this and with the amount of income you have you will owe nothing, and if you bring a tax statement from the bank that amount would be refunded to you
you can withdraw all of the 65,000 every month but you need a new 65,000 baht international transfer every month, can not be one baht less than 65,000 baht