@Paweł *******
please do reconsider your situation.
These COVID times have placed added difficulties for changing jobs as borders are closed...no longer easy to go to neighbor Thai Consulate and get a new Non B for teaching.
FYI...here is what a teacher outside of teacher has to do to get a Non B teacher visa:
My advice given to many via the stranded expats forums:
"As a teacher do yourself a favor...
Get a teachers contract..
Get the WP3 Thai work permit in cooperation with your school employer...
Have your school contact the Thai Ed Ministry to get your name placed on a list of teachers managed by the Thai Foreign Ministry...
Make application for the Non B visa for teaching ...
The Thai Embassy will look at the approved list and issue you a Non B for teaching and a CoE to enter Thailand."