You need to know that it’s OK to not be OK. It’s OK for the fear to take over. You don't have to always have a smile on your face. You are allowed to be in despair. You have to understand that it’s OK to break down. Let yourself kick and scream and sob, it’s OK to feel. Happiness isn't the only emotion you have. Acknowledge pain and sorrow and hatred and anger. Acknowledge your pain. Go ahead and try to figure out yourself. If you need to be alone to do that, then put yourself first. Don't worry about what others will think because you are important too.
But even if things seem dark, you need to know that you will be all right again. Eventually, everything will work out. I don't know how long that will take, but it will happen. Sometimes, you have to ask for help. It doesn't make you weak or stupid, it makes you human. It’s OK to accept help when it is offered to you. You are allowed to rely on someone when you need them. You can ask that someone for a hug when you just need to safe and cared about.
So please, let yourself be human. Let yourself be you. It's OK to not be OK.