It's okay that you don't know how to go on, the pain and grief will sting for a long time, but trust me with time they will sting a little less. In time you will be able to smile again, though at first you will feel like shit when you smile because you will feel like you are betraying them, but trust me the pain will become less and less and get replaced with an endearing memory of them. For now just focus on getting through the day, getting through the hour, and let time do its thing. I am really sorry about your loss.