Breaking conventions has been a thing for about as long as conventions themselves. No need to be hard on yourself. Next thing you should look at is Malbolge, very convention-breaking ;)

It looks like cat ran over the keyboard ( + _ + )

The solution is not to stick strictly to prefix, postifx, or infix notation. Instead, all three should be valid.

All these should be equivalent:

  + a b + c d + 
  + + + a b c d
  a + b + c + d
  a b c d + + +

More insidiously, these should be equivalent:

  x = a + b
  = + x a b
  x a b = +
  + x = a b
  x = a b +
  x a + b =

Don't be disappointed. That's cool! You've independently discovered something.

>>> Maybe I've spent too much time with Forth, but the given example didn't look bad at all to me. Quite the contrary. [...]

>> A lot of people said this, why building this I had no idea of how these languages looked. Now that I know about them my project looks like a cheap imitation of them :(

> Don't be disappointed. That's cool! You've independently discovered something.

I completely agree with mkingston's comment. Whether or not this project resembles other programming languages is beside the point. What truly matters is the joy you had building it. As Alan Perlis wisely said, "I think that it's extraordinarily important that we in computer science keep fun in computing."

This is a fascinating project, and in that same spirit of playful exploration, I'd like to share a minimalist, esoteric postfix language for drawing on a canvas that I built some time back: <https://susam.net/fxyt.html>.

you may want to browse https://codegolf.stackexchange.com for a while as well. There are all kinds of weird task-specific languages that can give you lots of ideas.

You can also look at this polyglot thread with 65 languages https://codegolf.stackexchange.com/questions/102370/add-a-la...