I Want to Make A New Cactus Block

Hello, I want to create a new cactus plant that remains only one block tall, without growing. I noticed I was only able to add one texture when adding a plant, so I used the add block feature instead, where I could add the different textures to the sides, top, and bottom of the block. When I tested this in-game, it didn't take long to realise that I had made a few mistakes.

For one, it looks like this (image link attached). Other issues that I know how to fix include it not breaking when placed next to another block (including another of the same block).

https://imgur.com/2jQV9cQ

I basically re-textured the Vanilla cactus block.