Your specific questions on dosing and changing the timing need to be answered by your doctor.
You were prescribed short-acting medication. It works very differently than long-acting (XR). So, you could possibly not do well on short-acting but do well on the long-acting version of the same brand of medication. The short-acting releases all the medication at once and then wears off. Long-acting releases gradually over the course of the day so you don’t have the same severity of peaks and valleys. Some people prefer short-acting formulations, but many can’t tolerate them well. So, keep that in mind.
ADDitude Community Moderator, Parenting ADHD Trainer & Author, Mom to teen w/ ADHD, LDs, and autism