Read G-Code and execute it on Arduino

To make it easy for people to help you please modify your post and use the code button </> so your code looks like this and is easy to copy to a text editor. See How to use the Forum

Your code is too long for me to study quickly without copying to a text editor.

Also use the AutoFormat tool to indent your code for easier reading.

Have you considered using the GRBL program ?

...R