I want to ask this as gently as possible--Have you considered that there might be OW in your H's life?
I say this not to cause you pain or alarm, but because MANY of the things you've said were the EXACT SAME SCENARIO as my sitch & in many, many others here who have discovered OP.
H getting increasingly distant, lack of intimacy, telling you that YOU were showing no interest in him/what he was doing, wanting to separate..AND on top of that your H is gone/on business A LOT.
I know your first instinct (like mine was) is to defend him, and your marriage and your values. I understand. BUT, you need to be prepared for the possibility with your eyes wide open.
I hope and pray this isn't the case for you, but if it is you really have to prepare yourself. Take time. Do NOTHING out of intense, reactant emotions.
YOu are still in the very early stages of all of this. Be patient with yourself. Let yourself FEEL THE PAIN, and realize that you need to be strong for your children.
Things WILL get better--- but it will take a long time and you need to take care of yourself along the way.
HUGS, my friend. We are here for you!!!
M- 18 T-21 S-14,11 & 10 BD 6-18-2012 (OW-EA) H moved out 11-3-2012 10-5-13 Me- I want a divorce. I want to move on w my life. 11-25-13 Jointly filed.