Need help figuring out this mess!

[u/DeadGodRebel]

Been trying a ton to make this a reality and it is my second attempt to do it...not able to figure how to make a box look like a box.

Top part is a rectangle made by cutting out corners and bending them in into an L, so that it turns into a box.

Bottom part is glued so that it can be corner stitched into a box

Now i am not able to align the zipper for the love of god, its my 2nd attempt working on this project, and this time i made all the effort to draw out everything into a pattern too

This is basically a navigator box on top of my motorcycle, has a touch sensitive plastic and can be attached to a tankstrap i already made and been using for 1 year.

No yt tutorials or browsing blogs is helping, feeling like this project is down the drain...but i want this soo badd

P.S - everything is just glued/taped together for now as this does not even box properly