Mastitis?!

My left boob has been hurting for the past 24 hours now, it’s got a little lump and when you touch it’s hot, and really tender also has a red mark. I’ve also been having body aches and chills, I’ll be really cold but super sweaty, and have the absolute worst headache ever. I went to the doctors today she didn’t say it was mastitis but she gave me a prescription incase it gets worse in the next 24 hours, should I just take the medicine? I feel so sick and haven’t been able to sleep because of it. I’ve been just doing Tylenol for today to help with the body aches and headache but it doesn’t seem to help me.