Do not - DO NOT - let your H bully you out of money that you DESERVE.
So he's discovering that it's more expensive to have two households than one? Boo hoo
So he thinks he can get more custody? This from the man who has been spending three hours a week with his kid?
So he doesn't want to pay half of the childcare costs - so you can WORK and support your child???
Honestly, any judge would probably laugh in his face. Your attorney told you this is a reasonable settlement, then it is. So he is resorting to bullying you, because he thinks he can pull one over on you that way. DON'T LET HIM.
It's a big mistake women make - giving up their financial rights in the divorce, in hopes that he'll come back. Don't let him play you like that. You need all your resources to plan a solid financial future for you and your child.
Keep contact to a minimum. When he brings this stuff up, tell him that's for the attorneys. Refuse to get sucked in.
In retrospect, was he a bully in the marriage? Or was this totally out of character behavior?
(Btw - this is not uncommon, for a guy to agree to one thing, then talk to other guys and decide he got "taken" in the divorce. My ex would probably tell you the same thing, even though our divorce was very fair and I actually gave up a number of things I could have won in court, just because I didn't want to deal with him any more).