Fuzzy head after zapping - Brain damage??

I have just got a zapper and have been using it for a week now. The third day I had a splitting headache, nausea and a strange, smelly stool. It passed and I felt great.
Then after zapping for a week I read in the forum here somewhere that zapping for longer than the standard 7/20 x 3 I could possibly get more results. So I tired zapping for 15/20 x 3 and at the end of it I felt exhausted and my head was really starting to get fuzzy. As time passed after the zapping it got fuzzier and fuzzier and I was exhausted and had to sleep for a few hours. I was initially worried that I had zapped my brain and had brain damage! I was extremely tired and found it difficult to get out of bed in the morning. I couldn't concentrate to do any work. But after 24 hours of the fuzziness and after another zap at 7/20 x 3 and a good sleep last night I feel much better. I had the same smeely stool too. Today the fuzziness seems to have lifted and is nearly all gone. I zapped the normal 7/20 x 3 this morning again.
I was just wondering if anyone has had a similar experience? I live in Japan and don't have a synchrometer so can't test to see what it was. Any pearls of wisdom out there? Tweet