I Broke My Best Friend's Study Plan

So last week, my best friend Alex and I had this perfect study plan to ace our finals. We were going to split up the chapters of our history textbook and review them together over coffee at the library every day until exams started. It was all set, right down to which sections we would tackle each morning. But then something funny happened, I ended up staying out late at a party with friends instead of hitting the books like I promised Alex. The next morning, she was waiting for me as planned but no amount of apologizing could undo the fact that my part wasn't done. We still managed to finish most of it on our own, but now I'm pretty sure there's going to be a fallout when we get our grades back. I can already feel this knot in my stomach thinking about how let down she must have felt knowing her friend couldn’t even stick to one measly study plan.