Seems like you are asking for a course of action..Your W wants to be roommates, so maybe that is ALL you should be.
Roommates aren't necessarily friends, or do everything together. Maybe you need to get a bit of your own life?
Maybe you don't say a thing to her and:
Open a seperate checking account, paying your portion of the bills (1/2)?
Have a different bedroom in the house.
Start doing some things you always wanted to do. Think big....maybe learn to fly? Maybe scuba dive? Maybe a trip somewhere for an adventure you want to do? Hunting or fishing?
Also think small....maybe join a bowling/darts/pool/basketball/soccer league? Something that gets you out of the house a night or two a week?
Maybe join a gym and work that into your schedule a few days a week?
The thing is, you can't control her. You can only control yourself. You don't want to end it yet, and you aren't ready to draw a line yet, so be indifferent. Don't be very available. When you must talk to her, be cheerful, be direct and exude that you are enjoying life. You might have to fake this at first, but don't ever fall back into being needy. She has to see that she isn't the only one that is looking at life differently, and it sounds like she isn't 100% committed to leaving either, which is good.
The thing about drawing a line is, there is really no going back on it. If she reacts negatively to it, you would have to live with it.
