I have been bending over backwards for him and this is where you've been going wrong.
From now on resolve that you, and you alone, call the shots. You're under no obligation to toe his line, and if he's not willing to arrange contact with you direct he doesn't get to see his ds and, more especially, as you've said on your earlier thread that he only wants to have ds when he's at work so he can palm him off onto his parents and keep his spare time for his new woman.
I'm relieved to know he won't be present at the birth, but there's no way you should allow him this privilege even if he asks to be there.
As for seeing newborn dd, he'll see her when YOU decide it's convenient and you won't be hiding yourself away in another room to suit him or, more probably, his new woman who doesn't want him to spend any time with you.
Don't put his name on dd's birth certificate. You won't be able to name him as father unless he accompanies you to the Registry Office and I would suggest you refuse should he offer - please know this won't prevent you claiming child maintenance for her.
This man has treated you appallingly. Start getting angry! He's the scum of the earth and not fit to lick your shoes let alone be a father to your dc. Take no notice of what he/his family/his friends are saying as you know the truth and eventually the truth will out, as it always does.
Take your mind off your misery by concentrating on your ds and your dm and don't allow yourself to wallow for longer than 20 minutes in any 24 hour period. The worthless twunt is not obsessing about you so don't do him the honour of fixating on him and/or the hurt he's caused you.
Please understand that he can only "make everything so much harder" than it needs to be if you let him, and you can choose not to let him
As many thousands of women who've found themselves in similar situations can affirm, You CAN and you WILL get through this and create a wonderful life for your dc and yourself.