Oh I feel for you so much, I really do.
It is good advice to take each hour at a time...Everything changed in an instant, and that is going to take a while for your brain to reorganise itself. And every time you see yourself in the mirror, or feel the pain, it probably brings it all to you again.
I have two marks on my arm, they are permanent, where he gouged out the flesh. I see them and I am back there again. In that ten minutes that turned my world, and my children's world upside down and back to front.
Plenty of rest, cry when you need to, but I was advised to not cry too much in front of the dc's, by the social worker, they needed me to be solid, at least to them. But cry when you can, crying is so healing.
When you are a little way down the line, there are people here who can help you make sense of stuff like MILs reaction. Often, these patterns are trans generational, and you may find stuff that you hadn't expected, in terms of attitudes and behaviours, but that is not for now.
Take very gentle care of yourself.