Are these items all good for my geckos?

Enclosure: 20gL
Heating/Temps: ZooMed UTH/90F:81F
Food: Mealworms - bred by myself and gutloaded, feeding 5 mealworms a day - yet it takes around 3-4 days to fully empty the dish
Water: a big, shallow dish on the cool side, away from the heater
Supplements: Repti Calcium with D3 for dusting and without D3 for the cage, Fluker's Liquid Vitamin Supplement for the food
Hides: 1 moist hide on the warm side, 1 dry hide on the warm side, and 2 dry hides on the cool side

Right now this is what I have for my geckos and they are still losing weight. I am just making sure that I'm doing everything right for them. I'm going to be using Oxbow Carnivore Care to feed them on a daily basis. I cannot take them to a vet though, because the only vet clinic who takes reptiles (still an hour drive away) didn't answer my calls until the 5th time (over a 3 hour time span) and they were EXTREMELY rude to me by telling me to stick Echo into a freezer even though he's still alive. I am certainly not taking my animals there even if they need it. People are such jerks. I'll try to take care of my leos myself.

So, all in all, am I doing everything right for my geckos?

I know I already said this on your other post, but I hope poor echo gets better.
Everything that you listed sounds good and safe, but I only have research, not not experience.
It never ceases to amaze me how cruel people can be.

I hate to be repetitive, but you have posted about your geckos a couple times now. It is highly likely they have parasites at this point, as your husbandry seems good enough that it would not cause this. The only way to fix parasites, once a gecko gets into decline, is to treat them with medication. I'm sorry that the closest vet you found does not appear to be a good one; I hope you will continue looking for a suitable vet.

It's just hard to find out what to do. I also realized that I might be overdosing on D3, since I was feeding them that on a daily basis for a month. I honestly don't believe they have parasites, so I will try my best with them and see how everything goes. I just got all this stuff this week, so I can't expect immediate results. I have to at least let it kick in. My fiancé was talking about how Viper's tail is looking like it's getting bigger, today.

FTT is always a possibility with any well kept reptile.