You don't know for sure that you're D is going to happen. Do NOT think that way - you need to believe that you can save your marriage. You are still pretty early into this ride... I'm still hanging on on my end, and just this week things have gotten better for me (or "us"...) - and it's been 9 months!. There are never any guarantees, of course, but you need to try your best, because you just might be able to pull it off - many others have too.
You had a talk, give it time to sink in for her... She needs time. Right or wrong, fair or foul, she still needs time, and maybe so do you. This won't resolve in a few days, most likely... Keep working on your DBing and read (or re-read) DR, and follow Michelle's advice. I went for the longest time seeing no improvements....other than things stopped getting worse. It got to the point where when nothing bad happened on any particular day, it was a good day. Now, things are slowly getting better still.
You can get there too, just take it easy, and don't panic. Try not to hurry up the process (I know, easy for me to say - been there...) but take it easy. Figure out things you can work on for yourself, try to do things to make yourself happier (I know, also hard to do) and enjoy your daughter while you have her - she needs to see you strong and in control, too.
Hang in there, things will get better.
Me: 46 W: 46 M: 9.5 yrs D4, D9 D filed by her 11/3/08 Agrees to try rec at mediation 1/28/09 Says she still wants D in counseling 3/25/09 W and I back in DB counseling (!) 8/20/09 3rd Bomb 9/2/09