Can a Self-Employed Individual Write Their Own Employment Letter for a METV Application?

And than it becomes time to close down. Sorry, as this page is called Thai Visa advice it is not called how can I stay inside Thailand and i do not care on what kind of visa. You apply for a visa that fits your purpose of stay or face the consequences of being an illegal alien, like jail, court session, deportation and blacklist between 0 and 99 years.

If you found the visa that fits your purpose of stay and you may have additional questions feel free to open a new topic.

You cannot work in Thailand with any Tourist Visa...single or multiple entry METV.

You need to have permanent residency in SA to be eligible to apply for a METV

You want an METV, in another topic you want a Non Immigrant O visa based on being a volunteer. You are self employed?

The Non Immigrant B visa with work permit, to be officially self employed and be able to do some work while in Thailand seems to me the better option

Where are you going to apply?

Best is asking to consconsulate you are applying. Requirements at each consulate varies.

What's your nationality?