I am prone to mastitis and will often go through bouts of if - have it 2-3 times over a few months and then nothing for a while. At times i felt like giving up as it's so painful but i didnt want to stop for that reason and pushed through it.
With DS I never got it until xmas when he was about 5 weeks and then had it alot. Luckily I was reading 'Baby Love' and she mentioned about things called blebs. I had a close look on my nipples and basically in some of the spots where the milk comes out the skin grows over which means the milk backs up and then you get mastitis. To fix them you have to either massage in the shower so they pop (doesnt hurt) or use a sterilised needle and nick that bit of skin - both ways the milk releases and if you get them in time you can avoid antibiotics. So maybe check for those but actually hold your nipple and give it a squeeze so milk comes out and you will see if you have any of these as a white spot will appear. I had to always check for these with DS but went on to feed him till 14.5 months.
With DD i never got the blebs again but got mastitis a lot at the start as i just had alot of milk, the pain was excruiating. As well as antibiotics I also go for ultrasound at the physio. You may have to ring a few to find out where to get this done but it really helps break down the blockage, you go for a few days. expensive but worth it. i hadnt had mastitis for ages but got it in november when DD was 12 months out of nowhere and away on holidays so just want you to go away and then show some random gp your boobs wink
anyway i know how it feels and thinking if i stop bf this will be over but once the antibiotics are working you'll feel much better about feeding again. keep going, you can do it smile