HELP - Spot the Mistake - Jacket Crocheted Incorrectly

Hello, fellow crochet and knitting enthusiasts!

I’d describe myself as a seasoned beginner when it comes to crocheting and knitting. After completing a few simple and successful projects, I decided to crochet this baby jacket (my first one, by the way—see photos) from a Rico pattern booklet.

The result looks pretty off—I can’t finish the jacket like this, can I? But I just can’t figure out where I went wrong.
That’s why I wanted to ask you for advice. Just to be safe, I threaded a green yarn at the 19 cm mark so I wouldn’t have to unravel the entire piece.

I’d appreciate any tips! Thanks in advance.

Instruction copies removed.
Mod

@laura-patricia
Welcome to our forum and platform.
Please do not upload copies of complete patterns here.
You can either contact the pattern's publisher directly, or perhaps you'll find someone here in the forum who can help you via PM (private message).
I wish you the best of luck.

As far as I can tell, you decreased on the wrong sides. Based on the pattern, you should actually be able to tell which side you need to decrease on. You don’t decrease where it goes straight up.