Welcome to NeuroTalk.
It sounds like you may be hitting the 40's age where your past sneaks up and tries to kick your butt. It will help if you try to learn the triggers that cause you to have a bad day. Many of us know we need to live life slower and with brain nutrition in mind. There is not much a doctor can do except confirm your symptoms.
I just learned of another ex-motorcross racer who at 42 is hitting the same wall.
Besides eating well, you will benefit from nutritional supplements. I have my regimen posted.
My best to you.
Mark in Idaho
58 years old, retired due to disability, married 33 years, father of three, grandfather of four, Suffered a serious concussion at 10 years old (1965) stopped most driving after last concussion at 46 years old (2001), Post Concussion Syndrome/Multiple Concussion/Impact Syndrome with PTSD, immediate and short term visual and auditory memory problems, slowed processing speed, visual and auditory processing difficulties, insomnia, absence seizures, OCD, 14 concussions since first concussion at 8 years old, Taking paroxetine and gabapentin for 12 years. Added L-Tryptophan and reduced paroxetine by half 3/2013
"Be Still and Know That I am God" Psalm 46:10