Aww, biyboo. I'm sending you hugs. Don't give a shit if it's un-MN, the situation warrants it. My Ex-P left me when our baby was 4mo, that was hard enough, but to do so while you are still pregnant? Your STBXH is a cunt. And I don't use the pure form of that word often.
I too was struggling to eat, to think, to move - but I had 3 older dc that had to be looked after, and I was BF'ing my DS3. I am now 5 months down the road, DS3 is now 9mo, and along with my other dc, is one of the four most wonderful things in the world.
I have gone through the dazed feeling, the confusion, the tears, the lack of appetite, and it is only NOW thatI am getting ANGRY with him. I am sure that at some point I will become indifferent to him, but right now I am angry. You too will work through all these stages too. But when you look into the eyes of your baby - you will know that everything will be alright, because you and your baby will face your new life together. You will have your own family, and he is not part of it anymore.
You do not have to have him at any of your antenatal appointments or scans, and you don't have to let him into the delivery room, and if it is in your birth plan that you don't want him there, the MW will not let him in. He has lost out on that opportunity by walking out on you while you are carrying your dc.
I am too far away from you to be able to come and meet up with you, but I am on MN most nights and if you need to talk or are feeling lonely, PM me by using the message poster bit on the blue bar where my posting name is (I will be changing back to my non-Halloween name in a minute but will post on here so you can PM if you want), and I will PM you back as soon as I am on here.
Stay strong, you can and will survive this, and YOU will have your beautiful dc at the end of it. He will be left with some scan pictures and some pregnancy books - which are a very poor substitute for being present at your dc's first smile, first steps, first everything like you will be.