I haven't been on the forums in a while but reading your thread from beginning to end I finally realized you've been trying so hard, pursuing, controlling your conversations, tip toeing around him, trying to be the better spouse, doing nice things, and yet all of this good behavior on your part gets you..... NOTHING!
He's in control, in fact so much control that he doesn't care what you do or say, he knows that you aren't going anywhere and when someone has that much power in a relationship, they will abuse their partners: mentally, emotionally, verbally, physically, financially, etc. etc. etc.
When people enjoy this much power in a relationship they will treat their spouses poorly. Luvless, you don't respect yourself enough and believe in your value enough and he takes you for granted.
How does that feel?
Feels awesome doesn't it?
No, of course not.
So you've tried everything under the sun and now you're mentioning "last resort stuff"
Do you want to do something that works?
Are you interested in really doing something that works?
But you can't do it half-assed and then come here and complain "I did what you guys said but he didn't care..."
Let me remind you, you started this thread on 11/24/09 and 91 pages later (yes 91!), you're still looking for things to try.
And then this crap from him saying "it's not you it's me", that's almost the male equivalent of the "I love you but I'm not in love with you" and if you've been on these forums long enough you know the possible reason for someone saying this.
If it was really him, why won't he improve if he's cognizant of the problem? Seems to me that if he can acknowledge that the problems are his, that he should be able to acknowledge a plan of action to remedy the issue. Is that what's he doing? A man who values his family and his wife would probably pursue some help and do something to make sure he doesn't lose what he has. But he doesn't attribute any value to what he has, do you get the impression that he doesn't care if he loses you? I'm sure you do. Don't you want to be in a loving relationship with a spouse that cares about you and loves you and would want to share a great life with you?
"I've had enough, I can't do this anymore! I don't love you enough to go through this for the rest of my life, I want you to leave."
You can't just say it without showing him you mean it.
"I don't feel comfortable with you sleeping in the same bed either, I want you to sleep on the couch/guest room."
Tell him you want him to move out, he can take a few weeks to find a place and move out.
He may argue, he may not care, he may respond a million different ways but this to be effective you have to show him you mean it. If he offers to work on the marriage or himself, you tell him you don't feel like doing this anymore, this is all too much work and he's never shown you consistent effort and even if he agreed, you're so drained that even if he did all the right things, you're not sure if you would feel differently and wouldn't want to get his hopes up. You tell him you've been feeling like this for quite some time and you just can't live like this anymore.
You give him fear of loss. You give him crisis.
You want him to fight for his marriage, you take it away from him. He changes his mind and starts to move in your direction, you keep your distance from him and keep him working for it, you make feel what losing is you like.
This is just advice.
In the end only you can do any of this but if you have truly tried doing everything and you still haven't gotten any results, the only thing left is to instill fear of loss in your spouse. It sucks that you have to scare them with fear of loss but up until now, they've had you, taken you for granted, what would get them to change their ways when everything else has failed.
If you do try this, just remember, no half-assed effort, you have to do this right, you have to make him believe you and this will require weeks & months of this stance - are you up to doing this?