hey. i have started to express breastmilk to fe...

hey. i have started to express breastmilk to feed to my baby he is 2 and a half weeks old. i decided to express milk as i keep gettin blocked milk ducts even though bubs emptys my breasts wen he feeds and my nipples are not healing up. i have gotten to the point where i dread feeding him because of the pain. he also doesnt seem to be gettin enough food as i will feed him for 30mins on each side or until he falls asleep which he does so often. but wakes up mouthing and trying to latch on to everything for more about 20mins to 1hours later. he has between 6and 9 dirty nappies a day. so i was wondering how much milk to express for each feed??