Hi mleigh, I think what you said was fine. In fact, based on his response, it seems like it was the perfect response! I would kill to hear my W say half those things!
I think it was the right thing to say because it's so true. My W before leaving tried over and over again to find a way to be able to go and not have to say it was her idea. She'd say or do something awful, I would react, she would spew about how it was all my fault that she did what she did and how horrible I am....you know the "dance of the MLC fairies". After, she would ask me if I felt "too uncomfortable" with her living with me knowing that she "no longer wanted to be M" or sometimes "no longer 'in love' with me" or whatever it was that time, that she could move out. Maybe go to her mothers or something.... It's a cop out IMO. A way for them to get the LBS to be the "bad guy". Not their idea to leave. Not their idea to not do things as a family, no, it's because YOU felt "uncomfortable". Great way to push the responsibility onto the LBS.
I think what you said was great. You made it known that you still want to be a family, that none of this was your idea and he needs to understand that this is all happening because of what HE is doing, not YOU.
If I were you I wouldn't "over think" this. IMO, what you said was perfect!