What you described about yourself sounds exactly like my H. He was/is always around but not available to me or our D16. I own my own business, take our D16 to all out of town drs. appts., cook, clean, work in his business. You get the picture. However, I do not control my anger well, and when I've had enough, out it comes in an attacking manner. Because of those attacks, my H dropped the D bomb.
Our sitch is also similar because of our spouses' behavior, with the exception of living arrangements. I still live at home and decided that I am going no where since I don't want the D, and we haven't discussed any details.
I try to believe none of what H says when it is negative, and I am not hearing a whole lot of positives. I am also trying to GAL, which is difficult in the beginning. It is hard to detach emotionally from someone you've been with for so long. You've gotten a lot of good advice above.
Keep reading DR/DB. I find that doing so helps me a lot and keeps me focused. When I don't, I feel like I fall of the wagon. I also bought The Five Love Languages, but haven't started it yet.
As 25 says, keep up the 180s, try a hobby with the kids. If you can show that you are truly committed to doing things with the kids, it may show her that you would be committed to doing things with her as well, and less of your hobbies that don't involved them.
M44 H57 D17 (special needs) M 18 yrs Bomb 7/2/12 Still living together