I did what I should have done earlier: I took a long walk and then I started new and this time I took babysteps. Doing that I found at least four things I got very wrong and the combination of those four (or maybe more that I still didn’t figure out) really confused me.
So tomorrow I will have a new look at it and if then there a still open questions I will ask again.
So: Thanks to everyone who read this and even more to those who answered!