Get him a bell to warn you if he is coming near you, shouting unclean. Encourage him to keep getting liquids in. He won't feel like drinking but a sip every 2-3 minutes doesn't sound much for an adult but it helps a lot. Not a large drink as very high chance of stomach rejecting it in protest at having to deal with being flooded, small sips little and very often.
If he starts wanting food later B.R.A.T (Bananas, Rice, Applesauce, Toast) www.wikihow.com/Follow-the-BRAT-Diet with tips of what to add after those so he is getting nutrition but not causing a revolt but avoiding food till active vom is over is best and then slowly tiny bits again
Leave DH to sort himself out if he is ill again, he is an adult. Tissues, spare toilet roll if needed, maybe a basin, saucepan or bucket if you are feeling kind. The saucepan will be ok after a hot wash. I have one designated as my puke pot. Plug his mobile in beside him so that if he gets a lot worse suddenly (but hope not) and you are in other room he can call you if needed,
if possible can you sleep in the room with DS tonight esp if he is young,
Before bed, layer up the bed with puppy pads/inco pads if you can get them, pad and fitted sheet and several layers. In case he is sick too and ends up vomiting or lower end - the pads are disposable and puppy pads are far cheaper than everything else and only slightly smaller than the much more expensive inco pads. Then he only needs to have the pad and possibly sheet pulled off and into a basket and bin bag in the bathroom and back to sleep. Not a massive changing of the bed procedure and you get back to sleep.
For you, you will need sleep. DH will have what he needs in your bedroom and you concentrate on keeping yourself far away and also your DS as its bloody miserable being sick and best to avoid it for you and your DS sake, too late atm for your DH