Adderall heart side effects

I was prescribed adderall xr 20 mg last week. Overall I’ve definitely seen improvements in my focus and attention but I’m concerned about the effects it’s had on my heart. I just did some weightlifting, same routine I always do, and I noticed I could feel my heart POUNDING in my chest. I looked at my Apple Watch data and saw my avg heart rate (resting and active) has gone up by 10-15 bpm. I tried to finish my workout but I just got too tired and had to stop. Definitely feel lightheaded after and needed to lay down. I have no history of heart problems and even got an EKG done a month ago and I was found to be very healthy. Im going to stop taking it now. I’m bummed because I felt like the drug was helping me in other ways.