How can I use Hinge loss for Multi-class Support Vector Machine algorithm?

I have coded a Multi-class SVM classifier using Hinge loss as loss function. I worked on the knowledge in this article: https://cs231n.github.io/linear-classify/.

But instead of decreasing and converging, my loss function increases to infinity after few loops.

I attach here file .m. Could anyone show me how I can fix this bug?