Excellent advice above, in my opinion.
It's very early days OP. Give yourself time and acccept that it will be cr*p for a long time. But taking positive action will help.
Best university I ever went to was going through separation.
Exercise: great for thinking in a way that keeps your head clear.
Friends: some will not want to know as they 'dont want to get involved', or will hear STBXH's side, or they were 'his' friends. You'll find out who your real friends are.
Goals: set targets for yourself re what you want for the future. What settlement will you be happy with? What do you want for (any)DC? Aim to do a 5k. Whatever. I've written my list for 2013.
Counselling: I cant make out from your OP if you've excluded it. If so, why so? I found it excellent, although I would caution that counsellors are like shoes. One size does not fit all. I got a recommendation from my solicitor!
If you really cant face it, try to figure out what went wrong. Don't duck from where your responsibility lies. You don't have to admit it to ex but admit it to yourself. Why did you marry this man? What did you get from him? What was good about your relationship?
Stages of grief: there is no going round it, you have to go through it. Accept that.
And big yourself up at every opportunity. Your self-esteem has taken a blow (may have been undermined for a long time). Celebrate every achievement. At the start, it may be small things e.g. I got out of bed and dressed properly. But pat yourself on the back for being strong.
Good luck.