It is okay to be sad. Being happy ALL THE TIME can actually lead to a not-so-happy life. Whenever you are sad, dont feel the need to put on a smile and say you are ok. If you dont feel ready to tell someone. That's ok, I'm not saying to vent every time you're sad, That's up to you. All i am saying is don't lie to yourself. Because then your brain will be happy and your heart will be sad and that can cause anxiety, self confusion.