Probabilities. Odds are jaw pain is just due to pain in the jaw (eg tmj). You're right that people with angina may get pain that spreads from their chest to their jaw and, less often, can get just jaw pain alone, but what is causing your pain depends on your profile. Are you at risk for heart disease? Can't answer that here of course - you need to be evaluated by your family doctor.
Sounds like. A whole lot of worry to me. First, you need to make an appointment with your family doc to rule out cardiac problems and perhaps a dentist to evaluate the possibility of tmj. But it would also be very helpful to see a psychiatrist for this type of "worst case scenario" anxiety.
Yes. Yes, left jaw pain can be related to ischemic heart disease. Unlikely. However if concerned, see your MD ASAP. More likely TMJ related if you have TMJ.