Sick neon tetra?

I have a neon tetra that i think is sick. I've asked a couple of questions about him but still not sure what to do. He has lost an eye don't know if it happened at the store or in my tank and dosn't school with the others just sits at the back and twitches is this a sign of aggetation and neon tetra diesease. He also has on the bottom of his caudal fin a cloudy/white bit and might be finrot. Although all these signs he still eats. Could he just be scard if he did lose his eye in my tank, i have notice he has been like this for a couple of days. The other fish i have in the tank are 1 gourami, 2 black widow tetras, clown loach and flying fox could any of these fish attacked him the gourami dosnt seem bothered or aggresive to the neons. So confused can you help me. Put him in a bowl now what should i do