@Alma **************
since you made a comment that you've been doing this for years you are not considered to be a tourist by the immigration laws - even if you consider yourself as one - hence I stick to the opinion of getting a visa for long term staying.
But hey, of course you can choose to continue abusing the system of Thailands generosity with their visa exemption scheme - I mean as long as it works, it works...
Entry into Thailand, no matter what visa you hold or not hold, is at the discretion of immigration.
When they decide a person is trying to stay in Thailand long term on tourist entries, they will eventually question it and put an end to it...