HR in 150-170s with normal exertion. GP, Cardio and ER did many tests and said my heart is healthy. GP says some ppl just have fast hearts. Is it true?

Yes. Your heart rate seems to be normal. for good health - Have a diet rich in fresh vegetables, fruits, whole grains, low fat milk and milk products, nuts, beans, legumes, lentils and small amounts of lean meats. Avoid saturated fats. Exercise at least 150 minutes/week and increase the intensity of exercise gradually. Do not use tobacco or alcohol in any form.