Remind yourself that it is only a temporary badness. Nothing bad lasts forever.
Acknowledge that you do not deserve to feel bad just because something bad is happening around you. Your feelings are valid, yes, but it’s not somehow ‘coming to you’ to feel that way. You do not ‘have’ to feel that way.
Love the good things in your life. Count them. Say ‘thank you’ to them. Focus on them.
Find something to do with your hands. Whether it’s squeezing a stress ball or doodling or writing, move your hands and focus on that instead of the world.
Once it’s done, let it die. Tomorrow is another day.