how much should I be pumping

I EBF my 7 week old daughter and I don't think that I'm producing enough I have been trying to get her to latch on a bottle but it is being very difficult for me to do I've had others introduce it to her and she seldom takes it my question is I am going to pump and I want to know how much I'm supposed to get out of each breast and how much I'm supposed to get total and in what time frame so I can figure out what is going on because if she's not asleep all she's trying to do is eat and she's not trying to eat all she's doing is crying and I want to know if the crying is because when she does feed it she's not getting full the most I have pumped and that is in both breasts is 2 oz total thank you