WAW is angry and filing divorce

[SH_]

I have read DR and had 3 coaching sessions and have been reviewing the forums for over a month now.

My situation seems unique to me, although I imagine that it is not.
Background on my situation is that I have been married for over 19 years, we have 2 daughters, 17 and 5 yrs old. Our marriage has been one of ups and downs and like I imagine many have been. We have had communication issues over the years that I believe have left many un resolved issues that have finally piled up.
My W is now filing for D.
My W has threatened D over the years to the point that I only took it seriously for the first time about a year ago, but unfortunately as I began to look for help, she convinced me that we could actually work it out together without outside help. I asked her if we could try counseling, read relationship material together and she told me we did not need to and we could just do it ourselves. Boy do I feel ignorant, because if I had just thought I could find material like DBing I could have made an impact on my own to avoid this horrible situation now.
Initially I was confused when my W said she wanted a separation and so I did everything that Michelle advises against in her books, and I imagine that is what pushed my W to then decide a divorce was what she wanted. Initially she would tell me she wanted to work things out, but just needed space. She went to a marriage counselor and to visit our bishop at church. After her second visit to the counselor she announced that we no longer had anything to work out as she had discovered that our goals were to the same and that we just needed to end it. She went 2 more times to the counselor but decided she did not want to pay someone that was not helping her. She visited the Bishop one more time, and in a visit that I had with him after he advised that we could only pray that she may some day soften her heart, but I needed to focus on myself and my daughters for now. He would prefer that we tried and work it out together, but he said that would take 2 people to decide on that for that to ever happen.
She would never say specifically why or tell me what was going on, so my confusion led to daily bouts of depression and confusion. Also she went from appearing calm and not caring about the decision she has made, to very violent mood swings from happy to angry. She has tossed out so many things at me over the past 2 months of things that I do that make her angry and early on she would apologize, but that is getting to be less and less with each angry interaction. She is now regularly accusing me of trying to hurt her and do things behind her back. She says that we are still married until she files the divorce and we should tell each other everything. She says this while sneaking around, setting up her own bank accounts and searching for a place to live and not telling me what the plans are for proceeding with her plans for divorce.
Anyway I don't want to get caught up explaining all of my current frustrations, because I know from reading DR that I need to be cautious in believing what she says and does and to focus on myself and GAL.
I am really trying to implement the Last Resort technique, but I am struggling with putting on the happy face in spite of the pain I am feeling as well as just going about my business without telling her. The challenge I am finding is that as I am going out to do the things I need to GAL, she seems to become suspicious that I am up to something to harm her, instead of her being curious. She then reacts angrily.
Another challenge I have right now with the GAL, is after work I have my daughters that I am spending time with as my WAW has also detached from them a lot and I know they are both hurting from this. My D17 is very angry with her mom and my D5 is confused and all of a sudden having behavior issues that she has never had.
Basically I feel stretched so thin that I can't seem to keep myself together as I am trying to catch all of the pieces.
I have recently tried encouraging my W to speed up the D so we can be separate and possibly have some peace. I am not sure if I should do that, but the tension is so thick it hurts.
I will continue to post in small posts and I hope to hear ideas and questions that I can answer to gain clarity on my situation as the pain and depression is taking over more and more each day and my moments of clarity are feeling to slip away and more fleeting with each day.
I love my W and I know that I have created a list 20 miles ling with all of the things that I have done wrong in our marriage, but I don't know specifically what she is hanging on to and what is fueling her fire and spite towards me. It hurts a lot.

Me 44
W 44
D 17
D 5
M 19 years 12/5/2015
BD Feb 7 2016