Hi Gabriele,
Very interesting post, thanks for sharing. I don’t have anything relevant to add to your specific symptoms, but given you are a new to QS, I wanted to share with you some of my experience in self-tracking as well as a recent book in case it helps you get closer to understanding your situation.
First, I would start by referencing this response by @ejain in the thread What is next for Quantified Self. It echoes my own self-tracking experience over the past 6 years - discovering something new simply doesn’t happen often. Having said that, the truly new insights I’ve generated from my self-tracking data primarily came as a result of aggregating this data over extended time periods. For example, not a new insight (as I already suspected this!) but because I track daily health observations as well as hourly weather, I was able to confirm that my acute episodes of stiff lower back are highly-correlated to the relative humidity in the air during the observation. In the “truly new insight” category of examples, the key was not only analyzing over extended periods of time, but also tracking multiple domains - the “interconnectedness” as you say. In my case, my tracking spans spiritual, social, physical, intellectual, financial and environmental domains.
Second, there are also multiple references on this forum to the value of self-tracking as a process in and of itself, regardless of the insights generated from it. In my case, I have a few examples where I see improvements that I suspect are more influenced by my thinking about them more often and as a result of self-tracking.
Lastly, If you haven’t already, I highly recommend reading Matthew Walker’s book - Why We Sleep. The book has completely change how I think about sleep, in particular the different stages of sleep, and the importance of sufficient quality sleep on our well-being.