PCS does usually not effect IQ but it can cause problems with successful memorization of facts and the ability to process multi-step formulas.

You would be wise to get an assessment of your current functions and dysfunctions. An educational psychologist may be helpful. A NeuroPsychological Assessment is intense and expensive and probably far more than you need.

Until you tell us about your symptoms, there is not much else we can offer. Read the thread Vitamins. It suggests how to take care of your brain.