Sick of porn..

So my relationship with my partner has gone down hill since he has been watching all of his porn. I always catch him watching it even when we have had sex. The other morning I caught him watching it in the shower and that just crossed the line for me. I'm sick of it, I'm sick of being in the relationship because of it. I told him that it really makes me unhappy and that I don't think I can be with him anymore. He has been trying to be affectionate and loving but that's not the point, it's the porn. I'm so against it, I hate it and he knows that. I'm honestly going to leave if he doesn't do something about it. I used to smoke and he said to me it's either the smoking or him and as much as I didn't want to I stopped smoking for him! I'm really considering saying that to him. Don't tell me to watch it with him and anything like that because I don't want to do that it's disgusting the thought of it gets me really angry. How do I tell him and explain that I want the porn gone or I'm gone...I have work at 5am and he has an hour by himself before work and every single time I have caught him watching porn. If he does it tomorrow morning I'm seriously not going to be happy. What do I do to stop this? I can't do it anymore. We have a baby on the way and this is how extreme it's got and how much it upsets me that I'm not afraid to leave. Please someone help, i don't know what to do. I want it blocked off everything!!