Change lawyer if you can as yours doesn’t sound like an equal match to fight him and his lawyer’s demands!
Also-Try to connect with a women’s advocacy group: One that supports women from a feminist perspective and has experience in supporting women going through a divorce from a narcissist. Often, a divorce situation fuels the power and control dynamic - particular where a male ‘ego’ is involved. It’s often their last grasp at exerting power and control over their former intimate partner.
I wouldn’t be communicating with him directly at all. Don’t negotiate any further until you’ve sought a second opinion. A lawyer is meant to fight your corner for you and not wimp out and give in to his every demand! What’s your lawyer demanding from HIM?
Having said that, some things are worth going into legal battle for such as securing your financial future/where you will live etc, whereas who gets the toaster or Aunty Betty’s teaset…perhaps is not! Consider what are your ‘non-negotiables’ and stick to them.