This looks like a lunchbox sewn onto a backpack, and i'm not sure thats a bad thing. I appreciate bags with space and as long as the contents are not heavy this might work. I hope to make a spacious backpack for myself some day.
I don't care that it's not perfect, it looks great!! Now that you mention it I can see the sloppy edges but I wouldn't have noticed otherwise. I hope you get to make one that you like next.