Chin up, coccidia is rarely (in my experience anyway) severe enough in cats to cause fatal complications. If both of these cats are adults with a healthy immune system, then you simply need to keep treating the coccidia. I work for a vet, and the first thing we tell people when we find coccidia on fecals is that it can be very difficult to treat. If repeated treatments with albon have not worked, you might ask your vet about treating with fenbendazole (panacur). We will switch to fenbendazole in cases where repeated treatments have not been effective. Coccidia can cause a bacterial overgrowth which may be contributing to the diarrhea, so it may be worth having a gram stain done to be sure that you don't need antibiotics or probiotics for that. For that matter, probiotics may not be a bad move in general with so much going on in the GI on these kitties.
On a side note, coccidia is species specific. Cats, dogs, and birds can all get coccidia. But dogs can not get coccidia from cats, cats can't get it from birds, etc. For a while we were having issues with some odd looking coccidia repeatedly showing up in canine fecal floats even after treatment. We finally sent the fecals to an outside lab, which confirmed that they were not from a coccidia infestation in the dogs but a pass-through coccidia from rabbits. The dogs were eating rabbit poop and the rabbit coccidia was showing up on the dog's fecals.