Would he be willing to go to MC during the separation? Also, do you have any kids?
Your sitch sounds a lot like mine was. We had an in-house separation, H had a one-sided EA that he hid...badly, we had just moved to a new state and I knew no one, dealt with depression/anxiety, and H told me he didn't know if he could ever have feelings for me again because I'd hurt him too much over the years.
We went to weekly MC during our sitch and for probably 2 years afterwards. However, other than that, I steered clear of him. I got really busy, and if he came upstairs to watch TV, I went into my bedroom to read, surf, or watch a movie. I made sure to be out of the house when he came home from work quite often, and I forced myself to move past my social anxiety to meet new people through Meetup groups. I also was in IC for myself, and that kept me sane.
Believe none of what they say and half of what they do. Yes, this is hard, but you can do it.
Institute a 48-hour rule on anything you want to do or say to H...if, in 48 hours after you are calmed down and not emotional it's still the right thing to do, then do it. Usually it's not.
You have to get to a place where you know you'll be okay no matter which way your sitch turns out. You PREFER to reconcile with H, but you know that you'll be okay if it doesn't work out. This takes time and working on YOU.
If you find yourself getting anxious or emotional or overly-dwelling on your sitch, GET BUSY. It doesn't matter with what. If you stay in that spot, you'll just do something you'll regret later.
Your H is a roommate, an acquaintance right now. Polite detachment is the rule. You are easy, breezy, and calm. Fake it until you make it. When my sitch was going on, I'd get up and make myself breakfast, hum, grab a book, and look oh-so-happy as H got ready to go to work (it was during summer, and I'm off). I stopped crying in front of him or giving him any hint how torn up I was. Once he left, if I needed to cry, I did, and I set a 10-minute time limit. Then I got up and got busy with something.
I look back at that summer as one of the happiest of my entire life. I found myself, and I know without a doubt that *I* am responsible for my happiness, and I will be okay with our without H. Without reaching that point, I think reconciling and building a better marriage would have been impossible.
Get yourself busy. Find happiness. Your H cannot make you happy, only YOU can do that. Get to work on yourself, and give your H space. It feels counterintuitive, but it's the right thing to do.
Hang in there!
SD
Me: 40 H: 43 H had EA from 2/06-9/06 Bomb 5/06 Piecing since 9/2006 3/2008: Boundary setting 7/2009: Boundary crossing~dropped my own bomb. 8/2010: Marriage finally on track!