Stress is more likely to cause a relapse than a rough ride. Worrying about a rough ride that obviously stressed your body and especially your neck is the king of stress. Rest is not video games......They are stressors.

I bet your body was surging in lactic acid from your beat up muscles.

You do not need to be resting at all. Let symptoms be your guide. If symptoms increase, stop the activity. Jogging is rough on the neck and can put vertical loads on C-1 and C-2 causing inflammation, just like your bike ride. Avoid all stressors until after exams.

Caffeine should be avoided.

Studies show that people 80% of people who suffer long term PCS have a pre-existing struggle with depression and anxiety. Resolving that will be a great improvement.

The vitamins regimen in the sticky above helps many tolerate stress. Adding 5-HTP and L-Theanine also improves anxiety and depression symptoms without drugs.