You should try to take fluids as much as possible.
It might be hard to keep it down, but it's the best for you.
If you're feeling sick in the gut, you don't want to be having the sickness of dehydration either.
Remember that fluids can literally be anything that is a fluid.
You don't have to drink water. You can have soup if you want.
I would recommend you avoid carbonated drinks, since these might agitate your stomach, and you definitely don't want to drink milk or things full of dairy. That will just curdle if you're sick.
Since it's a virus there is literally nothing you can do to combat it, beyond ensuring you eat and drink enough. Drinking is the priority, however.
Get as much sleep as you can. It's probably best you remain bed-ridden for the mean time. You most definitely don't want to go out, not this time of year. And you don't want to pass on what you have to others.
Just sit it out and keep going.
If you do have heavy pains then you can try painkillers, such as Ibuprofen or Paracetamol, but stick to the prescribed amount. If you're unsure, then ask a doctor. If you take them regularly, and you forget if you've had any, don't take any at all until the next period you could take them. If you can't keep track of what you're taking because of head-aches and fever, then don't take anything. You don't want to risk taking more than you should.
