What a brilliant move.. separate rooms in mediation. That's a GREAT idea.
Down the line, which would you want more in your life... fuming at his injustice or focusing on your life. Have you read "Not 'Just' Friends"? A section in that book about forgiveness changed my perspective on the big picture of divorce.
It's always so much easier to get riled at the interloper, the other partner. The true culprit is your spouse. The more you blame 'her', him the greater a victim you become. You can do that, might even need to do that.. but let yourself go through the stages of grief rather than getting stuck.
Put your incredible soulful, loving, caring, postive energy into YOU. Be your best friend.