I have c5-c6 herniated disc and spondylosis...I feel like I want to crack my neck, is that ok or might make it worse?

Risky. With the diagnosis you have, it would be unwise to crack your neck. Proper physical therapy directed by your orthopedic physician would be the safest thing you could do to help with the present situation and to have a home program set up for you that will both help alleviate your present and future situations. Some of the sensation may be spasm which applying warmth to your neck could help.