All this advice is perfect:
Stay hydrated is a key not just for this illness but especially for breastfeeding
Normal liquid intake for breastfeeding should be 2-6 oz per hour ( I needed much more than that: 6-8 oz per hour)
Our family is JUST recovering from a very virulent and violent tummy bug, just as you are describing
Active emetic stage (throwing up) was about six hours
During that time, each of us was able to keep a few ounces of water down. After this phase, it was easier to keep 4-8 oz down per hour.
If you cannot get out to get electrolytes, a short term solution is 1/8 tsp salt to 4-6 oz water, sip as needed, along with the 4-8 oz of regular water.
Remember to take extra precautions for washing hands,your face, your breasts, etc. to not transmit virus to baby.
Spraying your clothes with Lysol will help. Even spraying cribs and sheets if you cannot wash them right away.
Using listerine or some xylitol based mouthwash will help.
If baby gets sick, take baby to urgent care immediately. Small little ones can be too young to ward off a bad virus, and it can go from vomiting to dehydration to infection in a snap. They will need intervention SOONER than adults. Personal experience.
Plus if your breastfeeding is compromised, it can throw baby's system off as well.
Do you have pumped milk in freezer?
If the throwing up is over for you, and you are hydrated again, breastfeeding will help little one.
But if you are still actively throwing up, I would feed with reheated pumped milk, pumping your current milk and throwing it out, until I was hydrated and able to nurse again.
Very best of outcomes for you, and I'm sorry if this advice is not relevant for you as I am posting late.
Let us know.