I noticed my breast is bigger, painful and swelling on one side. What should I do? I tried expressing the milk but there seems to be no milk already but i still feel very painful. The bigger breast has more milk supply compared to the other one.

If breast is painful and hard means engorgement. Apply cold cabbage to your breasts, massage and try pumping again. Massage and pump regularly, 3-4hours to prevent engorgement. If one breast is bigger than the other after breastfeeding, You have to feed/pump the smaller breast longer/more often to try to even out the size.