Hi W.:
Boy, do I feel your pain!! I had mastitis twice after the birth of my dd - once at 1 week postpartum and once at around 2 months postpartum.
The symptoms will go away quickly with the antibiotics. Mine were gone in about 48 hours after the first dose of antibiotics.
However, you should know that once you've had mastitis, you're slightly more at risk for getting it again. So, you're smart to be asking about prevention.
This is what I learned:
I got mastitis the first time, because my husband let me sleep through a feeding (he gave our dd expressed breastmilk) - he was trying to help me and I didn't know any better, but it set me up for plugged ducts, which then led to mastitis.
I got mastitis the second time, because my period started - my supply dropped during my period (conflict of hormones!), then came surging back when it was over. I didn't keep on top of it and I got a plugged duct, which led to mastitis.
This is what I learned:
1. You want to check for plugged ducts every day - you probably already know this, but they will show up as tiny white dots on your nipples. If you see one, do whatever you can to unplug them. If you have questions about this, I'm happy to share more - just email me.
2. Take a lecithin supplement. This has been proven to reduce plugged ducts.
3. Keep to a regular pumping/feeding schedule - the fact that you could only get one pumping session in probably set you up for the mastitis. If you need to change your schedule, do it slowly over 3 to 4 days.
4. When your baby starts to take a substantial amount of his calories from solid food, you'll need to be watchful of plugged ducts - it will take 24-48 hours for your supply to drop due to your little one's demand. Pump to release the pressure and check often for plugged ducts during this time.
I hope this helps!
My great-grandmother died of mastitis 1 month after the birth of my grandmother. My grandma still talks about how she never got to know her mom. Anyway, I am very grateful for antibiotics!!!
Best of luck, M.