Please, read these pages (or this site)
http://ezw.zapperwise.com/e_theory_practice.html

http://ezw.zapperwise.com/e_frequency_30k.html

For a detailed explanation of the action of the zapper, as I see it.

Please, check by yourself what I’m saying. I’m not a doctor and the acknowledge I show comes from Internet sites, as Wikipedia.

A Hulda Clark ’s zapper is a Direct microCurrent inductor using an optimal frequency of 20kHz to 40kHz (30kHz average) to help cross the skin barrier.

You could make a very rudimentary Direct microCurrent Inductor by using a 6 to 12V battery directly plugged anyplace into your body. Not very efficient, not recommended neither as is.
Electronic Current (electrons) will travel from the negative pole, through you body, to the positive pole. Anything in the path of this tiny current flow will be cleaned from any parasite in about 3 to 7mn – Effect is almost immediate. But well protected organs against the current, like the intestinal tract, the bladder, the lungs and probably the prostate (all hollow organs) will not be affected (or very little)

Another ionic current (positive ions) goes from positive pole to negative pole through your body too. That is why we recommend to put one or two layers of wet towel paper with salty water: To avoid metallic ions coming into your body.

On the zapper you have – and many others – we ADD the effect of harmonics created by square waves, to disable microbes by using resonant frequencies blowing them away.
This effect will travel through all organs, hollow or not, but takes much more time to act.

This could (conditional) explain why you had an immediate effect, but still feel same problems.
There is another point to consider:
If you get rid of parasites causing pain, you have eliminated the material cause, but not the damages done. Zapper only affects pathogens, not damages done.

A 20-20 instead of 7-20 session could be much better, if your body can withstand elimination problems created by so long active sessions (at least on the beginning)

Every designer has its own theory and experience about the frequencies he makes and uses in their zapper. That is why I recommend you to follow parazapper recommendations for its CC1 zapper.

Be sure to re-read the instructions for the CC1. Modes 1 and 4 require 10.5 minutes on and 20 minutes off. Also, the on cycles should be multiples of 10.5 minutes on so 21 minutes on would be good. The 20 minutes off can be varied from 15 to 30 minutes off from my experience.

A good way to zap the prostate is to use the footpads and have one on the back of each leg while sitting down. The current goes right through the prostate that way and is a lot easier than having a handhold wedged in an awkward spot.