The assertion Wiki makes that you won't improve after a year or eighteen months is wrong, many on this forum will testify to continuing to improve way after this. I'm 2 years 5 months post concussion only this last month I've made progress with my remaining symptoms and expect to continue to.

PCS is brain damage and the brain takes a long time to heal and recovery isn't a straight line it's more of a sine wave gradually rising. Then there are the psychological effects of long term illness to overcome - feeling ill can become a behaviour you have to unlearn. PCS can also cause low level depression which can be debilitating, we don't always realise we're depressed, we just think we're a bit down.

I know it's frustrating when you remember how you used to be but you have to remain positive and look at how far you've progressed, you will get there with a positive mind. Also, listen to your body and rest when it needs rest. It's good that you are getting regular sleep, that will help a lot. With help the brain has great capacity for healing and adapting, certainly enough to prove doctors wrong!