We collect stress and anxiety in any number of places. Jaw is one of them. So is the neck, shoulders, back, stomach, etc. etc. The problem is the stress, not the heart, jaw, not any imagined illness.
How to deal with the stress is the issue. There are different paths of trying to get a handle on it which can vary from person to person. No doubt you are familiar with some of them and you can decide what suits you best. We can try and encourage and support you.