Like Jilly I separated recently (a couple of months now).
I find it hard when dc are away. At the beginning it was horrendous.
And it's hard when they are around too because you are responsible for everything, and it's difficult when they argue as mine do and there is no one else to help keep the peace or distract them. It's hard to get anything done as you are interrupted the whole time. And they are needier because of what's happening and because it's all new for them too.
So I'm starting to see the time when they are away as my opportunity to do things for myself, 'recover' from having them with me, get jobs done etc.
It takes a while to adjust psychologically to realising that you can do what you want. I'm 41 and I still can't quite believe that I can go and buy a bar of chocolate when I want one because my PARENTS hardly ever let us eat it when I was growing up!! Some days I feel really exhilarated to think that I can buy what I want at the supermarket, get in my car and not have to tell anyone where I'm going etc.
There is some sadness but I think it will get easier. At the beginning when I was on my own I just thought 'what the hell have I done?' But I think some of that is because I'd never really been without them and having been with someone for 15 years never spent a lot of time on my own since my mid-twenties.
I am starting to enjoy my own company.
I hope things get better for you.