New to this!

[Rejoice]

Hello all. I'm new here but I'm very, very interested in giving DBing a shot and would love any extra tips on doing it successfully--I've been trying but backsliding here and there. Any encouragement would be great, too--i honestly feel like dying.

My husband (together 13 years, 3 kids 16-11 years old) announced a month ago that he is having an emotional affair with an old friend of ours, and wants a divorce.
I have been absolutely devastated for the entirety of that month. Panic attacks, not able to eat or sleep, sobbing all the time. (I have had the wherewithal to try not to do so in front of him.)
Overnight he went from my (admittedly cranky but awesome) husband to cold, and constantly on his phone or at this other woman's house.

My sister in law suggested reading DR, as her husband (my husband's brother) recently walked out on her and she had been reading it. I read it in about two days flat while also taking copious notes. It was the first hope I've felt in any of this. Browsing success stories here has been one of my few sources of hope since then.

When I have been able to go a few days applying a combination of the principles of 180 and LRT and GAL (side note, GAL feels very hollow right now, I'm sad all the time) he responds to me in markedly better ways, wants to tell me about his day, etc.

Then I'll, say, find a love letter from her to him about how sweet he is, when all I've wanted for years was his sweet side to reappear. Or he'll lie to me about where he's at and go to her house. And I mess up, out of all of that pain. I break the DB rules and bring her up. Or whatever. He told me tonight that the very next time I don't respect his space and privacy, he will move out (I just found that letter two days ago.)

We talked after the first week post bomb drop and I, desperate to keep him, suggested that since neither of us have a viable plan for moving out or any of the logistics of taking care of the kids, we just verbally agree to be separated but stay in the same house. We both love our home. I suggested that we work on becoming trusting friends and he is skeptical of that but somewhat in agreement. So that's our current status.

But it is so, so hard to see him all the time. Additionally, he still sleeps in the bed with me every night and is very much interested in being intimate up to three times a day. Our sex life has never been better but he tells me he's just using me until he's ready to move on. Having read the book, believing nothing that he says and only half of what he does, I don't respond to this and just focus on the fact that while he's saying such a vile thing, he's also kissing me. But it makes me feel insane.

He was talking to me constantly about how all of this is apparently my fault, for weeks. He even blames me for the verbal abuse he carried on throughout our marriage. But among all of these accusations I was able to glean some if not all of the ways that I did legitimately hurt him over the years. I was controlling and critical and often rejected his advances. I was bitter and angry and cold. I carried a huge load of anger through all of these years about the yelling, about a previous affair that we overcame, etc. As soon as he announced he was leaving me though, it was like that anger fell apart like the Berlin wall and all I have left is my love for him and my debilitating pain and anxiety over this situation. I feel like a brand new person without that anger and I can see how I acted clearly after 13 years.

I've got all my cheeseless tunnels listed and next to them, behaviors that are the 180 of each. I try to stick to them.

For the most part I succeed in being upbeat and positive in front of him.

When he tries to bait me into a blaming, finger pointing fight, I simply validate his feelings. (It feels so unfair to calmly apologize to him for my behaviors (which he simply doesn't like because they trigger his guilt) when he won't apologize for his atrocious and disgusting behavior and is actively moving forward with the OW. )

I love him, I love our family unit exactly as it is, and the horrific trauma surrounding my parent's divorce is enough for me to want to fight to the death for my marriage, even if just for my children's sake.

I've been going out with friends and being mysterious. Going to a support group for separated or divorced people. Going to see a lovely therapist to help me, rebuild me.

I'm trying to be sure to connect with my kids although they can tell I'm sad all the time but aren't sure why.

He and this OW actually had my oldest stepchild turned against me for most of this month but I wrote her a heartfelt letter and she has since come around. I'm actually applying some principles of DBing to restoring my robbed relationship with her, funny enough.

I want to know what more I can do. And I'm very confused by his behavior.
My husband is one that can completely close someone off from his heart in an instant but still be nice to them, because of his childhood trauma. And I'm afraid it's too late, so so afraid.
But tonight he ran me a bath. He's said he's excited for the bedroom later.

It's so painful to live this way. A lot of the time, I wonder if I should just cut him off sexually or something. However, sex is SO SO important to him, and I rejected him for so long, that I fear that would be a final nail in the coffin.

All of my friends say he's just having his cake and eating it too, and he is, but I think possibly, under that, he may still care and just feels completely swamped by guilt to the point where he's trying to run as far as he can away from what he sees as the source of these negative feelings, me. Maybe I'm in denial.

I get really lost in comparing myself to her, sometimes. She's beautiful and thinner than I, and of course she's such a great listener because she's a marriage and family therapist (yeah, how do you like that, a homewrecking MFT.) He's doing all the things he used to do with me, with her. Writing her beautiful letters, all of it.

However as part of GAL I've lost weight and started tanning (he always loved when I was tan.) I admit I've been so sad that I've been doing most of this for him though instead of myself, and he's always been very smart. He calls me out on trying to win him back and says there's nothing to salvage.

Any perspective would be welcome. Thanks all.