Adderall IR Booster Dose timing. Help. Please?

I was recently prescribed an afternoon booster dose of 10mg of IR Adderall. I can't quite figure out the timing on when to take it, though? I take my 15mg XR around 8:00. I feel it wear off around 4:30-5:00. I need to be medicated for evening with my family or I will turn into an irritable monster. 👿

I took the IR yesterday at 2:00, along with a Dr Pepper. (I think that's what screwed me up. Caffeine.) I did not fall asleep until 1:30 am and got 4 hours of sleep last night. I am exhausted today. I was also a cranky mess around 7:30 -- our kid's bedtime. Which is......not great. I want to be a good mom, and not snap at them over everything. My husband even asked, very gently, "Did your meds wear off?" after I got real bitchy with my cat for hiding in our daughter's room after I shut her door.

What time do you take your booster dose? Have you ever tried the IR first and then the XR later?

I'm lost, tired, and cranky. I don't wanna be.