for you and your DC.
How to cope, in general terms, you have to feel whatever it is that you feel. Sometimes you'll block it out so you can get other things done but you can't do that long term, it isn't usually possible and if it is, it isn't healthy. Ask for assistance with the practical stuff, I'm sure your DC will help.
How to cope right now, do whatever you want to do. If you can't sleep is there something restful you can do eg reading or knitting? Having a bath? What do you usually do when you want to relax? Try that.
If you want to sleep but can't drop off, take the pressure off yourself and just lie there being calm, you're still resting your body. Focus on relaxing each muscle in turn. Tell yourself you can't sort anything out right now in the middle of the night, not even your thoughts or emotions, because you're exhausted. Keep gently reminding yourself of that whenever your brain darts down a rabbit hole of thoughts.
If you're used to your husband sleeping besides you, you might find it easier to sleep on the sofa tonight or in the spare room if you have one, somewhere you're not expecting him to be.
Perhaps make yourself a hot chocolate or chamomile tea and put the radio on quietly.
I'm so sorry for your loss. x