Two spot bristletooth illness/injury

So my bristletooth tang has been fine since being in my tank for a couple months. Today I came home and he was laying on the bottom of the tank half sideways. After prodding him with the eyedropper feeder he started swimming around at the bottom. He won't eat anything. He will sit for a while between rocks and then all of a sudden dart out and blast the sand and then wedge himself between rocks not moving again. He seems to do it carelessly like he has gone mad. I got these photos of some damage around the front of his head. I am not certain if it is disease or if he got spooked and knocked himself silly hitting something. He appears normal other than the markings on the head, he had no such markings until today. All parameters are fine, no other fish or coral is acting differently. Anyone have an opinion? Hole in the head etc? Im getting the hospital tank ready now but no idea if this is something to treat or if he has brain damage from ramming something.

 

No eyes fine. That white spot on eye is a reflection from my light. Just the scrapes/wounds on his head and weird behavior. He was still breathing this morning but sitting on the bottom. Hopefully he was just sleeping and will be back to normal when I get home but we will see.

 

Also Ive been thinking maybe it's an anemone sting from my bubble tip. He maybe got scared and darted against it on accident.

 

He bit the dust. No idea why. My best guess is trauma leading to heart failure.