My eels skin is rubbed raw and isn’t getting better

[Anarcha0s]

Hey my 3 year old snowflake eels skin is rubbed raw from a rock he hid under (i didn’t realize it was rubbing his skin) so far I’ve tried E.M. Erythromycin and that didnt do anything. He is also not eating. Any advice on how to heal him would be greatly appreciated. He’s in a 75 gallon tank with a couple of clowns and a few damsels.
Parameters are
Ammonia maybe .10 ppm
Nitrite 0 ppm
Nitrate 20-30 ppm
Ph is 7.8-8.0
Salinity 1.024-5 ppm

 

[Webslinger]

raise the rock so he has more room. dose some iodine

 

[Anarcha0s]

raise the rock so he has more room. dose some iodine

Rocks have already been arranged so theres more room. Also ordered one of those tacky submarine aquarium decorations so he can hide in if he likes. I figured the smooth inside would be more gentle on his skin. Ill try the iodine! Thanks!