First of all, your skills may not be where you want them yet, but you made art (and it’s pretty good besides; drawing is hard), you are an artist. An artist early in your journey, so think of all the aspiring art students that make just terrible stuff while they learn, and be happy you aren’t doing it for a career while improving. :)

That said, I don’t really see what the AI added to it. Sure it colored it in, but you could have done that too, and it would have been another chance to hide some of the blemishes that you don’t care for, and give it more of your own personality. The personality is the art, as much as the thing that gets made.

It doesn’t have to be perfect to be progress. Keep drawing, keep drawing the sorts of things you want to get good at, and think about how you’d like to color them, and just try it out, use crayons, colored pencils, markers, or maybe a digital image editing program. I’m sure there are some good free open source programs for that. You don’t get good without lots of practice, so train those muscles to do the fine motor skills you want them to do, and train your brain to think about what colors would be best for what you are trying to depict (something AI can never really do for you).

If you like the ai stuff for yourself, enjoy it, but personally I’d be put off by it being used in a book. Even bad art that’s hand made is better than AI, imho.