The only thing that I might slightly agree with your doctor on, is that some parasites might be introduced to your body because you have a weakened system. Dr. clark blames that on chemicals that mankind has added to the environment that weakens your body, or else is preferred by parasites. all that other junk sounds like a scam to me.
Why don't you spend hundreds (instead of thousands) buy the herbs and cleanses that people on this forum testify to.
I personally don't understand why people are so skeptical about parasites. Why in the world would we think that every animal in the world has parasites but Homosapiens. I have had people bring me their sickly horses. I de-wormed them (saw a pile of worms in their manuare) feed them properly, and witnessed them putting on muscle and running and bucking and carrying on after a few weeks. If it works for animals, why not humans?

There are people who want to help heal others because they're good people and there are people who want to make a lot of money off possibly healing people. If your motivation is purely money (which it sounds like it is) how can you do a good job of healing people. I'm not saying your doctor is wrong, but it's not necessary to pay what he's suggesting. There are simple, cheaper ways to do it.

good luck,
janaki