WR, KML gave you excellent advice. Yep, your h is looking for you to resist all the way to the divorce court. Let him think he's got control over the situation and you get your own appraisal and let's see who comes out closer to the true value of your home. Maybe the person he has in mind is on the up and up, but who knows until the appraisal is done. Whatever you do, don't go out of your way to make the home spic and span as if you are having open house to sell the place. If something needs repairing, tell them. Be honest and that way everything will be on the up and up.
I'm glad you got the meeting over and done w/today. Hopefully your broker will help in finding someone to work w/you. Don't tell your h about the meeting. It's time now to keep some things to yourself for a bit.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.