It is impossible to tell based on the information provided if the throat pain is due to heart disease. It certainly sounds like you have a lot of things going that can be causing you suffering (insomnia, stress, etc). I suggest continued close consultation with your primary physician to see if further testing (e.g. exercise stress test) would be warranted.
I am not a dr., but if the pills that you are taking for the BP have an active principle ending in "pril" like Lisonopril or Enalapril then your throat problem may be a side effect of them.