How many mg is in a 10mg Adderall XR? Is it 20mg or 10mg all together?

I am currently taking two 10 mg IR Adderall everyday, however I been getting crashes. My pharmacist at CVS recommended that I switch over to 10mg XR. Saying the 10mg XR has 20mg all together. 10mg instantly gets released when taking, then the other 10mg 4 hours later in the day. He said that is why the Adderall XR only goes up to the legal prescription of 30MG in one pill. Because the IR would be two 30mg pills. (because the highest dosage that a person can legally take is 60mg per day). But my doctor says that Adderall 10mg XR only has 10mg all together in it. I am so confused. Was hoping somebody with experience with this medication can actually tell me how much mg of Adderal is in a 10mg Adderall XR pill. Because I did take one once that my doctor precribed from a while ago, then haven't took it for so long because I had a panic attack. And now I think that panic attack might of been because it was a 20mg Adderall XR (so 40mg all together) Which is 20mg higher then my normal dosage for the day. Please if anybody with experience with this could help me, I would greatly appreciate it! Thank you so very much!