I'm sorry your sad and I don't know what to say that would help with that since I don't know what has made you sad. But being bored is never acceptable. Go clean out a closet, watch TV, read a book, search the Internet for something like a dream vacation or how to make low-calorie recipes. Call a friend, journal your feelings, beat up your pillow, take a bubble bath or hot shower. Eat a healthy snack and drink a huge glass of water.
Remember that life is ever changing, and these feelings your are having will pass, and you want to be left feeling good about what you did and not angry that you let your emotions rule you. Hang in there.