Also, Ik this is insanely late, but you might want to turn filtering off. I use Godot, so I wouldn't really know about Unity, but I presume that Unity has this option as well.
I used Adobe Photoshop to create this tileset. I used a different program just to check the animation.
The program is in Japanese, but here it is.
http://yaosame.m22.coreserver.jp/apps/autotile/