Possible mastitis?

An

1 week pp and I think I might have mastitis? Baby girl eats regularly. But over the last two days I’ve developed a slighter fever, I get chills during breastfeeding that make my whole body shake— usually a hot shower helps. And today I think I’ve noticed a red patch that feels somewhat tender.

Pic is of breast, nipple covered.

What are at home treatments?

Does mastitis always require antibiotics?