The only thing a negative CT Scan means is you did not have a brain bleed or serious brain contusion. That is a good sign. Very few CT Scans ever show any evidence of a concussion. They are done to protect doctors from liability if there is a bleed. The problem with that is most CT Scans are done in the ER within hours of the impact. Research shows that most brain bleeds do not even show in CT Scans until about 72 hours after the impact. Even then, they are usually of no consequence.

Brain imaging occasionally finds evidence of past bleeds and other injuries when no symptoms ever manifested previously.

I encourage you to try to let go of tracking your history. Noting seven months and three weeks suggests you are too focused on time. Try to focus on little victories with no regard for time past. You will do better.