Need advice

I need some advice on how I should either help or deal with a situation. My fiancé and I have been together for a little over seven years and have two small children. He gets stressed very easily and when he does he says things like o I hate my life or I want to crash the car in a wall (with just him in it). He is angry a lot and takes his angry out on me verbally. I don’t know how to deal with it or even how to try and help him without him taking my head off. I love him to death but I don’t want my children to grow up and see that behavior and think is ok. What would you ladies do?