I think you are majoring on the minors. Just relax. Ultimately, its not about the day to day readings, but about the overall trend. Don't think about each data point being life and death, instead look at the trend of the entire cycle.
If you overdose a bit one day, or under dose another, its all good. The main idea of the entire fishless cycle is that it is supposed to be less stressful. Try to relax and just keep going. Keep researching other aspects of your tank - stocking, plants, lighting, fertilizers, rescaping the hardscape, etc. Try to keep busy with other aspects of the hobby while you wait.