Anorexia and heart rate

Patient: I’ve recently been diagnosed as anorexic. I’m just barely in the normal weight category with my BMI… I’m 5’7″ and around 118-120 lbs. However, my resting heart rate has been over 90 the last few days and now is about 110-120 bpm. I normally have a higher resting heart rate, like high 70s or 80s, and I do have both anxiety and depression, but this feels extreme. Any thoughts