I believe it's good that you can see what it is your old self wants to do (like rescue her) and yet have the strength and wisdom to know it didn't work in the past and it won't work now.
I think she'll try to make you feel guilty, b/c she'll play every card in her deck before this is over and done. Sure you played a part in the downfall of the R, but she brought it to this point and she will have to be the one to work hard and grow enough to have a new M (if it's with you). That's not to say you have nothing to do. In the meantime, you need to take classes, or read the right books, mix & mingle with the opposite sex, or something to learn how to deal with over-bearing women. She's not the only one who needs time & space from the location and the M.
Time, distance, and her getting the right kind of help is the only hope for a future together (but don't you dare tell her!) Do you know why you shouldn't tell her? B/c she needs to think you have had enough of her and you're not interested any longer.
Look, I think I know what you "wish" she would do.....but she won't. So, You need to develop a social life (and do not give her reports when demanded) b/c you are single and it will help polish you up a bit. And if she calls demanding details, how will you handle it?
I truly hope she'll stay with her folks, but when she tries to use them as her instrument to get to you, what will you say to them?
When she cries on your sons' shoulders and tell them daddy won't let her come home, what will you say to them?
You need to nip this in the bud b/c you usually get caught off guard by her. Tell the boys that you cannot live with her again until you can see vast improvement, and enough time alone side of the improvements, before you would even entertain a thought of sharing a life with her. Don't leave them in the dark by not talking to them about their mother. Besides, they need to know how unbalanced she is. You sure don't want them to think she is the role model for them when they start thinking of M.
You're going to make it. You can do this!
((hugs))
It is not about what you feel should work in your M. It is about doing the work that gets the right results. Do what works!