Catrin: I will admit that it does take some time to figure out how to get the correct amount of tension for this to work, especially if the only adjustment barrels are on the brake levers. But I'm sure LBS can check and give you more info.

My only other suggestion is to simply put everything out of your mind and go for a ride, and enjoy it. That doesn't mean that I am trying to belittle any of your issues by any means, simply trying to get your head in a different spot where you can enjoy the pedals moving in circles again.