Thanks, AndrewP. I am in Massachusetts, where there is actually no such thing as "legal separation" - here you are either married or divorced, so yes, the agreement does not need anyone to validate it other than the two of us. It also is not necessarily enforcable, for that reason. I just want it because when I talk to him (and our MC has witnessed this first hand) he does not hear what I'm saying, he hears a distorted view of it that is quite often the opposite of what I'm saying. However, so far, when I've emailed him, we've had more productive conversations because we can go back to what I actually wrote!
Me: 45 H: 47, M 23 yrs., T 27 yrs. S6 & S13 BD: 10/23/16 11/20/16: In-house Separation 12/5/16 H goes to IC , stops confiding in me 12/29/16: Start MC 2/4/17: Trial Separation/H moves out