I am seeing doc soon but am very sad because if my rest heart rate is already 100-120 then all my hard excercise could be completely damaging! :(?

Heart Rate: You definitely should follow-up with your doctor, but do not despair about your excercise until you learn the cause of your elevated heart rate, .

See your doc: Seeing your doctor is the right choice here. There are exercise programs that will work for you. In fact, wearing a heart rate monitor while exercising and keeping the levels at 50 to 75% of your max will make for a better work out.