Have you ever tried using homeopathy? Here is a link to an instructional site that I have been using for a decade +. FYI, homeopathy works on humans, animals and plants. Remedies are generally available on line (amazon.com) as well as directly from the remedy manufacturers. Homeopathy is a necessity to know in today’s environment, generally safe to use (I do not use pharmaceutical products), suitable for use with infants/elderly. Instructions and further education available from this link.
https://joettecalabrese.com/blog/3-homeopathic-remedies-for-mastitis/
Look for search bar in upper right of page… put in mastitis.