I had head injury in April 2008 and suffered loss of memory but recovered soon. The fol symptoms still persist

a. I have lost my concentration to an extent that i have to focus my self deliberately to understand 4 lines script and to assimilate it while before the injury i used to have glimpses of any script and comprehension of it immediately

b. My retention power is almost lost i have to work so hard to memorize something

c. i have developed stiff neck forever around the neck pain feel like muscles stiffened even on right shoulders

Plz guide me if there is a solution