I don't know about Michelle's book. I know it's on Wal-Mart.com and I'm sure it's on Amazon.. you may have to order it? The book I'm reading right now is called "Codependent No More" by Melody Beattie. It's awesome. It has been so super helpful in how I think and feel about myself and I know will help me change for the better. I don't know for sure, but you might also check into Al-Anon meetings... I've only been to one, but I could identify with every single person in the room--they were all codependent and very similar to me... they may not have been with an alcoholic, but they were in the same boat.
If you want to make it work between the two of you, professionally or otherwise, you will have to trust him. Which I'm sure is hard because that's probably where you started. Codependents tend to be very trusting at first and then when its gone, it's very hard to get back. But it can be done. It will just take some time. One of the biggest pieces of advice I can give you is to mind your own business and give him space.