If your chameleon is keeping its eyes closed most of the day and its not something in your husbandry (like the incorrect light, supplements, etc.) then your chameleon is sick.
Did the vet run any tests?
I'm wondering about the feces molding over so quickly....do you have mold anywhere else in the cage (like in/on the soil)?
You said you dust with Reptivite reptile vitamins...Since most feeder insects have a poor ratio of calcium to phos., its important to dust them with a phos.-free calcium powder at most feedings to help make up for it.
I dust twice a month with a phos.-free calcium/D3 powder to ensure that the chameleon gets some D3 without overdoing it...leaving it to produce the rest of the D3 from its exposure to the UVB light. D3 from supplements can build up in the system and cause problems while D3 produced from exposure to UVB should not as long as the chameleon can move in and out of the UVB.
I dust twice a month with a vitamin powder that contains a beta carotene source of vitamin A. Beta carotene (prOformed) vitamin A will not build up in the system like prEformed sources will. However, there is controversy as to whether all/any chameleons can convert beta carotene so some people use a little prEformed once in a while. Excess prEformed may prevent the D3 from doing its job and push the chameleon towards MBD.
Calcium, D3, vitamin A and phos. all play important parts in bone health (and other systems) and need to be in balance. You need to look at your supplements, what you feed to the chameleon and what you feed to the insects when trying to balance them.
If you look at the fish food and the reptivite you will likely find that there is prEformed vitamin A in both of them...so you will need to be careful using them.
You said..."The cage is in the corner of my bedroom next to a window"...does your chameleon make any popping or wheezing noises when it breathes? If its cold or drafty and the cage is damp at night your chameleon could develop a fungal infection or respiratory infection.
You said..."I was force feeding him fish food mixed with peanut butter and water"...there are better things to feed to the chameleon than these things. You could use baby food veggies, a slurry made from bugs, etc.
You said..."he hasn't eaten in 3 days"...that in itself is not bad, but along with the other symptoms, it is of concern.
