Flashbacks. Memories. Memories.

so today i was sitting on the floor in my room and all of a sudden i had a flashback. or a memory, or something in between. im not sure. but in this vision i saw me grabbing the wheel of the car i was in when i was 15. i saw myself causing the accident that changed the lives of every single person around me. It may not have been a real memory tho. see what most people dont know is that my long term memory has really been messed up since my car accident. I have no gage of space and time. I cant just feel what day it is. I dont know if things happened 2 months ago or 3 weeks aho, and I dont know if my thoughts are memories or creations. this is something that has plagued me for years but i have said nothing about. But now, at this very moment im wondering if i actually didnt cause our car crash, then why is my mind creating this image? And if it created this, what else has my mind created? how much of what I remember is real?