Dunno. Calmer than I thought I would be. It definitively helps that I have been around way longer than just the Klopp era and don´t identify everything my club is about with just his person. It will be weird seeing a different person on the side lines, but it is certainly not a complete foreign thought for me. The club is bigger than anyone.
What just happened was the way Klopp often predicted. He would leave on his own terms when he would realize that he is not the best man for the job anymore. This season has in quite a few ways been unacceptable by Klopp´s standart and it became very obvious for a long time that the club and the team would need new impulses to recover. I personally thought it would be a major overhaul of the squad under Klopp, but now the overhaul starts with Klopp.
In the end, similar to his tenure at Mainz (and people stating that his time there was a sign of failure need to have their head checked) he left Dortmund in a way better shape than when he took over and for that he has earned himself massive respect and gratitude. It might also be the best time to install a new coach. Succeeding Klopp was always going to be a huge job, but the really lackluster season might lower expectations a bit for the new coach.
Quite frankly, I don´t know how I will feel about it in the long run, because I have no idea how big the effects of this change will be. Ask me again at the end of the Summer window and I might have a more definite answer. The potential for great football is still there (financial strength, improved youth work, club structure) and that is to a large part thanks to Jürgen Klopp.