Sore breast :/

[kristybabe]

I have a sore left breast, am scared of getting mastitis. There is no actual lump as such but above my nipple to press is fairly firm and tender if j push on my nipple also... I have massaged it whilst he is feeding but it's still firm :/
What should I do to avoid it getting worse and make it better

[mummy2Luca]

expressing it while i fed on the other always helped me, warm compresses can help and just keep feeding on it.