When i sleep, according to my husband, i can breathe in through my nose, but i am unable to breathe out through my nose but instead let it outmy mouth?

Mouth breathing: You could have some abnormality in your sinuses that cause this. For instance, a deviated septum or broken nasal septal bone blocking the way. It could just be the way your brain is programmed. You could buy a strap used to prevent mouth breathing that keeps your mouth closed while you sleep. Check with an ENT if you are concerned. They can definitely help you get an idea of the cause of this.

Simple solution: is Chin-Up Strip They are designed to re-direct breathing through the nasal passages to provide a training nasal breathing.