That's very scary for you, I understand. Unmumsnetty hugs. How old are your kids?
First, some logical thinking. You may not get it. If you get it, it may be mild or moderate. You may have two uncomfortable weeks where the kids eat cereal for dinner and watch TV non stop. Most people will not have severe symptoms and need hospitalisation.
OK. Now, plan for the worst case scenarios. The likelihood they will happen is close to zero, but it can help to have a plan.
Do the kids know how and when to call emergency services ? If not, teach them (if verbal). Are there any trustworthy neighbours around who could ensure your children's safety short term in an emergency? If so, can you ask them to be an emergency contact at this time?
Talk to friends. While they might not be happy to have your children now, I bet at least some would take the kids in an emergency ie you are extremely sick.
Your aim here is for someone to be able to call emergency services, for people to know there are children in the house who need to be cared for if you become seriously and suddenly ill.
Back to likely scenarios. Imagine you geot a bad flu that requires two weeks rest. What plans can you put in place for your children now? Do you have a playpen (if littlies)? Can you make a box of 'to play when mum is sick' toys? Do you have panadol for fever and ache? Can you make and freeze some soup so there is food is you are too unwell to cook? If your kids are older, can they make toast, tea, warm up baked beans etc? If not, teach them now.
When calm, sit down and brainstorm a list of ways to prepare for being moderately unwell at home for a time, and your emergency plan for...well...an emergency.