He may be being bullied by the other fish, so I'd try isolating him a see if he feeds. Generally a school fish like a tetra needs to be in groups of six or more to dissapate aggression between fish of the same species. Your tank is overstocked, so this isn't an option. I'd either remove the rummy noses and bristlenose (may be small for a pleco, but fat too large for a ten gallon)
Then hopefully he will stop being bullied, if the tank has fewer inhabitants.
The one
inch per gallon rule, which works on small fish would give you
7.5 from neons, 4 from rummys, 9 from the phantoms, 4 from kuhli, and eight from the bristle.
This gives you 32.5 inches! I'd get rid of the loach, bristlenose and the rummy noses, then the fish will be slightly more comfortable.
Good luck!