The boys

I look at the boys and think to myself...why would he do this to them.  Me I can take it but why it to our children.  It makes me so sad because I'm trying to shield them from any hurt but I know I won't be able to.  They don't realize what will happen in the future because it looks status quo to them.  They ask about their dad when he's at work..."when is he coming home"....what do I say when he doesn't in the future.  Their lives have been thru changes in start of daycare, me having to start work soon, not being able to be there for them much in the future for school projects, being able to take them places during the day and spending time with them like I did, and having me as the primary caregiver, not to mention the possiblity of finding a new place to live...smaller (which is ok) and sharing a room, only being able to bring a few things with them.  This is why I'm sad and I find it so hard.  How do I explain to a 6 year old?!  He/both will be mad at me for this...I think I can take it because he heard me tell his dad to leave, so it will always be my fault.  I feel guilty, so guilty about that.  I'm damned if I do, damned if I don't.  I don't think I'll get over this.