Just a minor point-
LLL is a retailer, not a breeder. I'm sure they may breed a few things from time to time, but their business model is mainly buying from suppliers and breeders and reselling. Nothing wrong with that and LLL seems to be very very good compared to most retailers from what I have seen. I've even sold a few lizards to them in the past and they were good to deal with in that relationship as well.
One more minor point-
Parasites usually only come from feeders if your supplier of feeders also keeps lizards. Most (such as pinworms) are host specific. It would be highly unlikely, for example for crickets purchased directly from a cricket farm would be contaminated with pinworms, unless one of the workers had lizards as pets at home and his lizards were infected. Pinworm cysts are super sticky and super tiny. The result is they are easily spread around when doing normal things like cleaning and feeding and watering a collection. Once spread they wait for a host to come along and eat them, and can last quiet a while while they wait. If your lizard has pinworms, he most likely got them from his parents and grandparents and great grandparents while the breeders were cleaning, feeding and watering their collections. Or from your local pet shop where the employee who scoops your crickets picked up cysts on her wrists from a lizard for sale when cleaning earlier in the day and then she drops them into the cricket bin when chasing crickets around for customers later. When your lizard has a healthy immune system, they are no problem and go unnoticed. When the immune system becomes compromised (stress, cold temps, lack of nutrition or bad lighting, etc) then the pinworms have a party in your lizard and explode in numbers.
At least that is more or less how a famous reptile vet once explained how pinworms work to me 20 years ago. Maybe thinking on this has changed today. At that time he felt pinworms were maybe even species specific (bearded dragons different pinworms than chameleons)- don't know if that was ever proven though.
Most parasites are at least fairly host specific- meaning what infects your lizard won't infect you or your feeder bugs or live in the dirt in your backyard (unless you have wild lizards living there), etc. There are a very few exceptions - like a relatively few types of salmonella for example. But they are exceptions.
Something to think about when choosing where to buy a pet or where to buy feeders and evaluating the risks involved. What else comes into contact with the animals- how many sources do they come from and how many pass through a caretaker's hands and how long have they been with a caretaker before passing along to the buyer. Breeders dealing with few species are going to a little safer in most cases than retailers who deal with dozens every day, many of which are wildcaught with parasites from the wild, stressed and shedding the parasites. The best retailers, like LLL maintain high standards of cleanliness to minimize risk to the buyer, but there is always going to more risk when dealing with a large retailer, and there is never going to be no risk, even with a very small breeder with very high standards...
And of course, once the animal is in home, there are risks there as well, which is why communication with the seller is important early on when a problem arises.
Of course it is very hard to say what went wrong in this case. Seems like the OP was doing a pretty good job to me. But with life, there is always some gamble involved. Really I'd rather see new owners pick something a little larger for a first animal- it really minimizes the risk a lot.
