For future viewers of my initial mail, after some days of reading the wiki, I finally recovered all my files using the method that is described at https://raid.wiki.kernel.org/index.php/Recovering_a_damaged_RAID. I overlayed the two disks with the most recent Events count (not the spare one) to files and I force assembled the array from these files. I was extremely happy when I saw that the array was successfully assembled and the Events count matched. I immediately backed up all my files successfully. Best wishes and.. Don't panic.
