Help soothe my medication fears

I just started on Adderall about a week ago, started on 20mg and went down to 5mg twice a day since it felt like too much. It finally feels like the general mind fog and not being able to figure out what I should be doing has gone, and I can wake up in the mornings now.

The only problem I have is when I'm taking it I become super aware of my heartbeat and I get soreness on the far left side of my chest. I'm going to talk to my doctor about it tomorrow but I'm worried that the medication is damaging my heart and I'm going to have to stop taking it, right before I start taking summer classes.

I know I'm probably just worrying too much since I used to have a problem with anxiety (that has gotten much better in the past few years) but it keeps popping into my mind and scaring me.

Can anyone please talk to me and reassure me that it's going to be ok? I know a lot of people get similar side effects but it's scaring me anyways.