I'm sorry to hear of your H getting his own place. I thought I'd write the following to see if it helps you:
1. View it as just a building. Buildings can be sold etc. It's people that make your R's, not buildings. If you reconcile, you can sell it and get a different one.
2. It might give you more space to decide what you want from your M.
3. If you are on friendly terms (I don't know your sitch) you could even get him a 'congratulations on your new house' card and buy him some stuff for the house so that when you go there, some of 'your' things are there and you won't feel so out of place. I did this before I went dark and bought my H a new chrome kettle to match his other kitchen stuff. His wardrobe was the one I had bought him a previous Christmas, most of my books were on his shelves including ones I wrote myself. It really helped. It may not apply if you're nasty to each other or barely civil though, as can happen after break up.
4. Think of it as just a transition place for him until he finds his way back. My H asked me to work with him prior to me going dark, so I did do, 2 days per week at his house. I had a photo of me on 'my' desk and my name on the login of his computer. This helped too, as it made his place feel like mine as well. Obviously this wouldn't apply to you but if you develop a friendship it may do in future.
5. Try to see the advantages of 2 houses. When he has your son, you get peace and quiet and to do what you want.
You have somewhere else to go 'for coffee' should you develop a friendship. If you re-kindle a R, which is possible, you can have a 'love nest' at his place. I got pregnant at my H's place
If you ever move back in together at some point in the future, you will have 2 of eveything (i.e 2 washing machines, 2 vaccums, 2 beds etc) so you can have a massive garden party and sell tons of stuff and either buy new stuff to celebrate your union or go on a cruise
Remember the only thing you can't reverse is death and the largest obstacle is your mind. It isn't over until you give up and even then it might not be because mine wanted me when I gave up.
