Dear Donna,
We live in busy times, our minds are constantly filled with things to do & we are encouraged to always be one step ahead. Slow down during Reiki & think about what you are doing in that moment & what you are feeling during that process.
It might help to spend a little time preparing yourself before Reiki. Listen to music that calms you, meditate, yoga, warm bath or say a prayer, etc. You may have to disentangle yourself mentally from your "schedule" and responsibilities, etc. before Reiki. Some people create a "sacred space" where they feel calm, away from the main stressors or attention getting aspects of their lives. With practice you will find that eventually you will not need to do this any longer, it will come naturally.
peace & joy,
holobon