Cake buckle shoji

Head injury? - head injury more condition_symptoms

I've got a blow on the head a few days ago. I do not know if I had a concussion or not. The pain in my head is still pretty bad. I hit my head very hard on many occasions in the past to break even the skin more than once. I think my question is, since I came to my head, I have to fight more than usual with reading and writing. Is this a coincidence, or is likely to damage of the past? If so, that this matter permanently or temporarily? Besides, I'm pretty terrible mathematics could progress due to injuries to the head? I read online, but I am not able to find a good source.