This might sound controversial but sometimes the best coping mechanism is to get distracted by doing some stuff. There are some things that you can’t control, and unfortunately graduation or friendship ending is one of them. I am genuinely sorry for your friendship loss, it must be really disappointing and stressful. However, starting working on some stuff like personal statements might be helpful, because it is something about your future. And working on your future should bring you the feeling of control over your life. Usually the feeling of control is incredibly important during the stressful times.