Yasha goby dying suddenly before my eyes, please help

[DooDeeReefer]

BTW, without a suitable pistol-shrimp, the container with the deep sand doesn't do her (no black spot on the ventral fin = it's a female) much good. Some small tubes or rocks to hide in or under would be better. If you use rocks you can add a bit sand where the rocks are.

Thanks!!! I didn’t know that. I knew the shrimp would dig the hole for them, I just thought they enjoyed being in the sand haha. I can make him something to be more comfortable in!! I do believe he has a spot on him. It’s hard to tell right now without his fin up but I attached another picture to help ID