Hi Anja,
I feel your pain

Since a car roll over accident in August 2011 I've had 4 more concussions, all of which took about 2 or 3 weeks to heal up. But this last one has taken 5.5 months and I'm still not healed up. I don't even have to hit my head that hard to reaggravate the concussion. We just have to be realllly careful.