I am exercising to try and heal from an accident, but i keep feeling fraying/tearing. muscles on sides of neck feel like they are not getting oxygen. ?

Whiplash: Healing is directly proportional to the energy absorbed during the injury. So, harder impact=longer healing time. Generally speaking, this is purely a muscular problem and worsens for a day or two, and then improves thereafter over days or weeks. Rarely does whiplash produce lasting symptoms over 2-3 months (unless a lawsuit is involved, then all bets are off).