I recommend buying Dr Sutters book for the basics on health. It will answer a lot of your questions, especially since you sound somewhat skeptical of natural healing still.
The cleansing order is:
1) Colon cleanse: You are doing a great colon cleanse, continue
2) Parasite cleanse: Do Humaworm or Barefoots dewormer
3) Liver flush
etc..
If your colon cleanse is causing that much of a detox reaction, either slow it down or don't do it for 3 days and then try again. For people that are highly toxic, it is often the case where they have to slow down their cleansing for 1-3 days, if it's too strong.
Your on the right path with Schulzes colon cleanser and it sounds like it's doing it job, just give your body a break for a few days.