he feels that I am being selfish because I alwyas knew he didnt want kids
He's being selfish, not you. You were careful with contraception, but none are infallible. He could have had the snip. Abortion is about a woman's right to bodily autonomy, not a man's right to opt out of paternity by forcing her to terminate.
I'm really sorry you are facing this. It's hard. I've had a termination by choice (another was due to an ectopic pregnancy, so I'd have died otherwise - most pro-life types will give me that one!) and never felt regret about it. But I knew it was the wrong time and I couldn't give a childhood a child should have. If you know this pregnancy is wanted, and you feel a connection with it, then terminating would IMO be a very bad idea. Pro-choice means just that. It's your choice. It's a woman's right to choose because it's her body. He has no right to pressure you or be angry that you won't exercise that choice at his convenience, especially when it would be so deeply traumatic for you.
His reasons may be heartfelt and sincere, in which case I think couple's counselling could help. Or they could be manipulative bollocks, in which case he is an arse. You will have an instinct on which. But none of them sound sane, in all honesty, other than the money. And the idea it will "ruin his life" is laughable. It's a child, not an agonising, incurable disease.
If he does walk away, bear in mind that CSA payments are not calculated when you get tax credits etc - it's a top up, so the child benefits from that parental money instead of the taxpayer. I mention that because it could make things easier financially for you, perhaps? I'd work out what you would be entitled to as a single parent in terms of state help, unless you're on a very high income. It will give you some clarity, going forward, if you know what position you'd be in as a single parent. You can also calculate what child support he'd have to pay, there are calculators for that online.
And finally - congratulations. Being a mum is wonderful. 