Problem with GIF making :(

Hey! I had this problem some time ago and hoped it would go away when I tried again next, but my GIFs are turning out really really grainy. I understand that GIFs aren't really a go to in the first place - but they were fine just some time ago and randomly started becoming barely legible. Before the question of "what did you change," I'll answer that right now and say nothing. At least I think I didn't, because I didn't touch my render settings other than my looping in the GIF exportation tab.

Here are some photos.

Here is screenshot of the original video.

Now in Photoshop, my current "save for web" tab looks like this.

But when I hit preview or rendered it, it all becomes super grainy and looks like this.

I noticed the icon stayed the same, for some reason. Also, a reminder - it wasn't always like this, and it wasn't gradual or slow! I had rendered this video a few times before and they all came out really nice, they just suddenly started turning out like that. Any help or advice would be appreciated ❤️

I've also changed around all the settings, some of them looked worse than before but none of them came even close to the quality I was getting before.

Thanks!