I read a book between 2000 and 2005 in the public library. It was in German language. I could not remember the picture or the title. I have a very far association with a hard cover.
The main character was a young adult, maybe a little younger. I do not remember if a boy or girl. If I remember this I have the picture of an angry and sad person in mind.
Through some circumstances, maybe nearly death, this person explores/could see that angels act as crows in our world. They help people with their power and all the humans see are crows. This is the reason why so many crows are near highways and other daily dangerous places.
In the later story a plant tries to destroy the person. The plant grows out of the persons heart with thorns and I think it had a pale color. I associated it with fear, anger and sadness, which would destroy the loving heart. One plant related story part took place at a grave yard.
It may be, that the person comes into a dark room, maybe basement at this grave yard, find the plant and eat some part of it.
I could not remember a special area where the story is taking place, but it was in the present "normal" world.
I would like to read it again, does anybody know this book?