Thank you very much for your answer Parazapper. You read my mind, I was about to write you a personal message when I see your post, given that you seem to be one of the persons with more experience in the zapper field.
I read in one of your posts that you also usded the zapper a few times without the paper towels. So I can be reasured that 21 minutes of copper tubes at 15hz is safe enough for one or a couple of times. Somwhere I read that the electricity would carry the copper in considerable amounts to the liver kidneys brain etc. But I believe you. Besides I read so many statments of users that afirm to be extremely cautious of not touching the tubes with your bare hands under any circumstance that I've got a bit paranoid.
So I guess that in my case it's just a bad coincidence or maybe a BIG dye off nerve damage that is causing all this pains and gurgling noises in one leg, chest pains etc, all of which started the following day after using the zapper. Hope they will clear out though, as 2 months and 1/2 is already enough. I will consider the chiropractor, although the pain feels more like a nerve thing.
So this helps me to go my new doctor not with a copper toxicity story, which would already be a problem as they already look at me as if I were crazy when I tell them about the zapper.