Want to create Child theme, but already edited Parent theme css files and some php files

I downloaded a WP theme and edited some php files and the css file to my liking (trial and error), and have been using that on my website – but didn’t create a child theme. This means any updates I do to the parent theme, will override my changes – so I’ve done no updates so far.

Is it possible to create a child theme now, somehow keeping the newly edited php files and css file that I possess by putting them in my child theme folder, (creating some kind of pointer css file to have the child override the parent) and then updating the original parent? If so, how?

Or should I just scrap the theme entirely, look for a new theme and create a child immediately out of that before I make any edits?

In case you have access to the original theme files you can compare them using a tool for that purpose such as this, then when you identify which are the modified files you load those files to your child theme.

This way you only have the modified files on your child theme and it won’t matter if any update happens after that.

If you progress so far isn’t that big or that important you can analyze to see which option is more time-consuming, doing this or starting over with a new theme.