Re: please don't hate me, help me... long.
Definately let him know that this is the way its going to be. If he just wants to argue and doesn't want to look at any of the facts, then just tell him you've made up your mind and you're not going to talk about it any longer.
My sister went through this and her SO ruined her whole pregnancy over it. BUT I know she would tell you that it was worth it and after the baby was home, her SO didn't care anymore because he fell in love with their DS.
My sister has an account here, her UN is mallorow if you want to talk to someone who's been through this and is glad they didn't give in. I know she wouldn't mind.