A stiff neck needs to be addressed. It can cause concussion symptoms to be worse. Therapy (chiro, NUCCA, PT, etc) helps but you also must develop good posture discipline so you do not undo the treatments. Your most important issue is posture when resting or asleep. Poor neck and head position during sleep stress the injury preventing it from healing. Good healing can take months of disciplined posture and therapy.

Think of this semester as your health college semester. Focus on learning to help your body heal. It is not just rest. It is proper rest and any needed therapy.

My best to you.