I decided to take things into my own hands and ordered a comprehensive stool sample through a local Parasitolgy company. It wasn't that expensive and they claim they will examine all stool samples for many parasites and will even examine an actual suspected parasite itself. Most regular labs don't specialize in it. If you can afford it, maybe you should think of something like that. There are many specialist labs out there. It took some research but I finally found one where I could order the test myself instead of begging my doctor to do it but the results still go to your doctor. At least I may get some answers.
I feel for what you are going through. When I started getting the parasites in my eyes, I got really scared. This is very frustrating and I cannot wait until it's all gone. Hang in there, they will eventually die off.