I wish there was another way around it, but there isn't.  Writers write.  Start small when you first begin to write, because you are also learning to sit.  I began with a thirty minute session.  Then I added to that time each day until I could sit and write for a  few hours (with a few breaks to the fridge or coffee pot).  There are days the minutes drag and there are days the hours pass by like seconds.  That's the way most jobs are.