I think you can best give up DTV for now and research other options such as a legit ED visa. And do this through an agency with the right connections and knowledge. But this will take time and money.
what were your previous visas? Because maybe they even have decided that you were doing business here already for years without the correct permits. Just my thoughts.
You are competing with local photographers and visa agencies. Also you do all kind of collaborations in Thailand which take away business from Thai so called influencers. This is my take on the reason for rejection.