okay so i got in a car accident about 3 weeks ago and i was fine and could remember all the events clearly, i wasnt knocked out and there were no signs of concussion then like 2 weeks later i started to get dizzy and have headaches and feal nausious. so i went to the doctor and he says it sounds like post-concussive syndrome...so i looked that up and it said it can last 3 months to a year and that kinda freaked me out... so can i get some opinions bout how long these feelings will last