Liz,
I understand what you want him to do--become mentally and emotionally healthy. Yet at the same time, I realize just how vague that may seem to him. I think as long as you are going to MC, you should write a laundry list of what you think mentally and emotionally healthy is --for all people. Define it, and give as many concrete examples as possible. I think that will make it clear to him exactly what you want, and will no doubt make it clearer to yourself what exactly it is you are looking for, and whether your requests are fair and do-able, or whether they are setting him up to fail you.