If you were unhappy in your job, quitting that job was not a mistake.
Quitting before you secured a new job however, was not very wise. Unless your skillset is one of those where you will get a new job without effort.
If you had the pocketmoney to pursue your dream job, all good. But if you were financially struggling and try to make a living out of creating video games, as a beginner, you are out of touch with reality. Not only would you try to make a living, but independantly. You would have had more expertise to go freelancer in your old profession.
Creating games is art. And as with most arts, the artists are usually struggling. With platforms to self publish and engines like Unity, it is super easy for hobby game developer to saturate the entry market. Which means free games, a lot of games and the paradox of "indie" games on Steam being usually successful. Those games are the exception, the ones that are professional enough to be accepted on the platform. But it does not guarantee success, as you can push most things onto Steam with a little effort if you self publish. And as you have seen first hand, there is no entry bar at all for games on Itch. So they have "over a million" games. They do not. It is a million projects in the game category. If you remove the double entries and the joke projects and super bad projects, unfinished projects and so on, you might be left with 200k games.
Why did people not download your game? Because they have to download it, and it looks like a mobile or browser game. How many of those did you download last year or ever? (Games that look like they should be a browser game). Except for testing out the competition.
Reminds me of the Tempest games. (I did not play your game, nor watch your video). I remember playing one with more colors and music. But it is still an "arcade" game. Those are not very popular, compared to streamable horror shocker games. Funny that. I would have guessed otherwise, because of the short attention span arcade games require.
Now that you know programming, you might want to create something with your existing expertise in engineering. Crafting games are popular. Like, the most commercially successful game ever is Minecraft. If you want to create another arcade game, maybe look here for inspiration. For fame https://itch.io/games/top-rated/tag-arcade and for commercial success https://itch.io/games/top-sellers/tag-arcade .
But if you do this as a hobby, best you do what is most fun to you. Trying to make a game that is successful as a goal is just as soulless as any other job. Maybe even more so for an artist.