The next time the issue is raised. just state that you need some time to adjust to the idea of separating things. I would then also say that I do not want to meet with a mediator about this situation. Leave it at that.
You are a stander and you will continue to stand for your marriage until you are ready to give up. You do not need to advise him again that you don't want the divorce. He knows it, just as he knows you love him.
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.
