Here is some stuff that i know:
* expressing is not a good indicator of supply. Babies are usually much more effective suckers than the pump.
* it's ok to have one 'good' breast and many women find that baby feeds better from one side than the other. Some women only have one breast to feed from and have enough for bub.
* perceived low supply is usually not really low supply, but your body adjusting to how much bub needs.
* keep offering breast to bub, paying attention to attachment (cos you don't want to hurt yourself)
* can you have a shower or bath or just skin to skin cuddles with bub - this can help release the good hormones.
* have you looked at baby led attachment? this can sometimes help give you better attachment especially if you and bub are relaxed after nice cuddles