Question from a sick FTM

I know that awful flu is going around and I don’t think it’s that but I do have something. Seems like a sinus/cold thing. But it’s hit fast and hard.

My baby girl is 1 month old and breastfed. My questions are

1) can she get sick from my milk?

2) do I need to have someone watch her out of the house to keep her from getting sick?

3) my left breast is a little sore but not feeling hot, how do you know if you have mastasis? (Spelling?) I keep seeing flu like symptoms can also be from that

I’m probably just being a little paranoid but I don’t want to be the reason my baby is sick.