Be kind to yourself. Don't expect too much from yourself. It's a big thing that you are going through and right now your emotions will be heavy and raw. And the divorce process is tough, even when it's you who initiated and wanted it. I initiated mine as my ex was impossible to live with and not very nice, but I still 'mourned' the end of the relationship and the marriage. Even though I am happier without him, I still felt it.
But it will get better. You just keep moving forwards, one step at a time.
Soon enough you will start to feel free and strong and liberated. You will.
Everyday, pat yourself on the back for your progress, whether it be fixing something yourself that you would have asked him to do, or ticking a box on the divorce process, or even just a day where you cried less than yesterday. Celebrate the little wins.
Practice lots of self care. Baths, early nights, chick flick + wine, whatever feels like a treat that's just for you. And make sure to eat, keep your strength up. Take some vitamins. Make your self as strong as you can be, bit by bit.
You will get there 