It seems that you have an eating disorder
which are frequently known to co-exist with OCD. This has nothing to do with the concussion
( unless you damaged a part of your hypothalamus
which is an almost impossible event)
This can severely affect your health. I would suggest that you see a psychiatrist
and a therapist. There are other issues that we would need to address. If you are not eating at all, make sure you dont workout.
Hope that helps