Can't do it anymore. what steps do I take?

My marriage is getting to a point where I feel like I'm breaking. I put in everything and my wife brings nothing to the table. She has grown cold. I can't do anything outside of work. She is digging us into debt. The sex sucks (when we have it). Sometimes I wonder if I married a narcissist. It's getting to the point where I'm contemplating suicide at work and making it look like an accident so the baby gets life insurance money.

We have a new house and a baby. My family says I should wait a one year and sell the house, act like we are moving to a better house then get my own place. Then contact a lawyer.

What steps should i take? I want to be happy.