How have you been dealing with your depression? Have you gotten any professional help?
The let's be "friends" schpiel does not always mean that's really what they want. It's something that can be said as a way of defining what you won't be.
I understand that you have been working on yourself. Your eagerness to have him see all of these changes can backfire on you. You want him to see it so much, you're likely to tell him all about it. Mistake.
I would leave him alone for now. Do not persue him in any way. The "accidental" running into him can feel like a manipulation or stalking. Neither one of these is good.
Read the book when you get it. Then read it again. Everything won't apply to you. Take what does and work with it.
The biggest thing you need to continue to work on is you. Own what is yours from the problems you brought to the marriage. Right now, I would just do this for you. You don't have to tell him or keep apologiziing. Just look at you. What changes do you want to make for you?
As hard as it is to accept, any changes you make have to be for you. Nothing else sticks and you can make yourself nuts trying to change for someone else. And why would you want to?