The answers to your questions are as individual as your fingerprints. No one on here can tell you what to do. You have to decide that for yourself.
In general, you have to let your W understand how much her actions are part of the cause to the breakdown of your M. You must discover what YOUR part of that breakdown is, and FIX IT! <img border="0" title="" alt="[Smile]" src="images/icons/smile.gif" /> In most cases, it's a 50/50 situation. Your W is obviously LBing to you.... but it is quite possible that you are doing the same to her, and you may not even realise it. <img border="0" title="" alt="[Eek!]" src="images/icons/shocked.gif" />
Try going through the Emotional Needs questionnaire and the Love Buster questionnaire with your W. At the very least, it will give you a clearer understanding of what your W is expecting from you.
It is a VERY BRAVE thing to do, for you to want to work on your M first, before giving up. It can be a treacherous road for some, but it's always worth it in the long run, to know that you've done all that you can do.
Be sure to figure out what you need to do for your Plan A. When that's become fine-tuned, THEN you'll be able to better decide just how long you should be at it.
Dr. Harley suggests a 6 month plan A... however, that is usually from the BS to the WS. It may be to your best interest to make an appt with Jennifer or Steve to find out what you should do. There are also a few other WS's on here who are trying to Plan A their BS's... they may be the best people for you to learn from (Lisa in London and Yellow Rose are the only two I can think of off of the top of my head).
Take care, and be sure to keep on posting on here as much as you need to.
Karen