XR is seeing less effective than IR but next appt not for 3 months.

So two months ago I was officially diagnosed for ADHD by a neurologist I was seeing for migraines. My first month I was prescribed 2 10mg IR Adderall to take as needed each day. Other than a few times of missing it as I was running late for class, I noticed a huge difference in my quality of life. Not only have i had nearly 0 mograines or headache days, they were multiple times a week previously and we think triggered by stress, I have been excelling at school and work. Because I am a full time student and work 15-30 hrs a week from home, computer science intern, i asked if there was a way to extend my dose better throughout the day so i didnt have to pick and choose the four hour chunks i needed to be productive during the day. So at my checkup appt, a few weeks ago, i was prescribed 10mg of XR as well as the 10mg IR as an afternoon booster. Due to some insurance and doctor and pharmacy miscommunication these were filled about a week apart. Today is my third day of taking the XR and I am starting to feel as if it is not nearly as effective as the IR. I initially chalked it up to the fact that my first day on it I was working on a 6 page paper I was completely uninterested in. But today is a normal work only day for me and i have still been extremely less focused, that is until I take my IR in the afternoon and then i feel great. I was under the impression that the XR would feel the same as the IR but just last longer, however i feel like it is far less effective so i cant wven tell if it is lasting longer honestly. I am frustrated because now my next appt is not for 3 months but im worried I am going to suffer through finals and work until then. I know I could make another appt to discuss this but then I would have to pay again and this has already been an expensive process . Is it common for XR Adderall to feel less effective and only last maybe 5 hours? And has anyone had success in asking for a higher dose from there doctor over the phone when getting the refill script or will I have to make another appt? I apologize for the length and any mistakes, I'm posting from my phone.