I'm not a doctor nor am I in the medical field. It would not be in your own best interests to take medical advice from me or any strangers on the Internet. Furthermore, this forum's rules strongly discourages from such medical advice.
My best suggestion is to stick with the doctors and their suggestions. As I wrote before, you might want to speak your regular doctor and have him refer you to a cardiologist.
Based on your info, you don't sound overweight. You clearly are sounding anxious and that can make matters worse, but you have had this higher heart rate for a long time.
Heart rates always increase after you eat a meal. the best time to measure your heart rate is first thing in the morning (after you urinate). I've no idea about your height or whether or not you smoke or you still have an infection. However, that info you should follow up with your medical professionals.