I had mastitis several times. It starts out with pain during letdowns. Then you feel tired. Then the affected area of the breast gets sore, and very full. Thats pretty much just a plugged duct. Then the pain, redness, hardness from engorgement, and fever sets in and it is pure misery from there. Latching is pretty painful on the affected side. I never had bruising, but that could be how you are showing the infection. I had reddish/purplish area's around the infected area. I also had the heaviness you described. It sounds like you have the beginning of mastitis. Hopefully with lots of rest and nursing you can fight it off. Good luck. I hope that you don't end up with a full blown case, it sucks! The one time my temperature was 103.6 after taking both tylenol and motrin. The other times it wasn't quite so bad, it was 102ish before taking anything and it would go down to the 99 range with taking something. I took Keflex 2 of the 3 times and it worked real fast, within 16 hours or so. The other time I took Levaquin and that worked fast, too. I hope you are feeling better soon!