My cousin is a single mum to a wonderful 11 year old boy.
It hasn't been easy for her, but as the alternative was an abusive bully who only saw the baby as a means of 'trapping' her with him, it was better than the alternative. A lot of people tut and groan about children needing a father, but I don't think this is true at all. Children need positive male role models, and if their father isn't one, they're better off without them. My cousin's boy has wonderful uncles who all adore him, and do twice the job a present but terrible father would do. I had one of those, and I now have nothing to do with him. I firmly believe my childhood would have been much better with a happy mum who wasn't always arguing with her husband, who had precious little to do with us other than to shout at us or get us to fetch things for him
She says the hardest thing is having to be both parents at once, and she constantly beats herself up for being a bad mum, despite the fact that her boy is an absolute joy to be around, educationally gifted, witty, considerate, thoughtful and popular with his peers.
From what you've said in other posts, your partner comes across as pretty selfish. Some of his comments sound really quite hurtful, especially when you've been suffering quite badly with symptoms. You have to ask yourself the question 'what will he be like when the baby's here?' - do you think he'll have a major change of heart and start being supportive? Or will he just stay the same, or worse even?
I don't envy you your choice, but you'll know in your heart what the right thing to do is. Could you maybe spend some time apart? Stay with family for a bit? It'll give you both space to think, and you don't want to make any rash decisions, given the circumstances. Or some counselling? If he's willing to give that a go, it'll tell you a lot about his commitment to the relationship.
Good luck, whatever you choose to do