You are wrong. Not just slightly, but badly enough that I could not in good conscience ever recommend you for any programming job until I was convinced that you had learned from your mistakes.

I leave it as an exercise for you to read Applied Cryptography and figure out how to crack your own scrambling algorithm. A hint. If you xor 20 times it is the same as having done one xor. (Albeit against a different key than any of your original 20.) So it does not matter how well you have managed to confuse yourself about what you have done, to an attacker this is an xor, and if they get 2 messages written in English encrypted this way, they are going to have little trouble reading both of them.

Just because you don't see how they can do it, doesn't mean that they can't. Or even that they will find it particularly hard.