Hey, I am very sorry to hear that. I am also 5 mo pregnant ( with a boy) and my husband and I have been together for 8 yr (married for 4)he does not think my pregnant body is unattractive and for a man to say that to a pregnant woman is disgusting! Pregnant women are sensitive enogh without being told they are unattractive.
I believe the normal family unit is best for a child, mother and father living together and all that. But I do not think you should have to stay with him just because you are pregnant (congrats by the way- due date?)
if you have talked to him and told him how much it bothers you and he doesn't care, then I would take that to mean that he doesn't care about you. When my husband and I first got married, he had a porn collection, nothing he watched all the time but, at the time it made me very uncomfortable. I asked him to get rid of it and because I wasn't doing it to be health forum, it really did bother me, he got rid of it. He has over the years accumulated some more and now it doesn't really bother me because I know it is not a problem for him.
I will tell you that I know someone who is married to someone addicted to porn and she is miserable about it. It has really messed up her self esteem. I don't think you should subject yourself to that. There are men out there who will adore your body when it is carrying their child. That is the kind you should have. If he has some perfect porn star body in his mind as what you have to look like- even after the baby is born your body won't be the same. He needs to love your body because it is yours. I don't mean to tell you to leave, but if he doesn't love you enough to get help for his addiction, there is a serious problem with the way he loves you.