I'm at almost ten months post-concussion and doing SO much better. At four months, I was still a mess. It takes time and space, but it does get better.
I got my Prozac prescription bumped up a bit, and it helped with some of the hopelessness.
I also felt that my cognitive function improved after I started taking Algal DHA and acetyl-l-carnitine supplements. It might be placebo effect, but hey, at least it's improvement
Playing SuperBetter helped me see things from a positive rather than negative perspective during that time frame.
Good luck.