Won't take a boob for more than a few mins!

Useonfire

My DD is 3 weeks and 1 day, and she is starting to not feed for very long at each boob. She'll do like 6 or 7 mins on one side, then act completely full, then an hour later, maybe 4-6 mins of another. I had oversupply issues with my DS (though I was an EPer for a few months) and when I pump, I can usually get about 4-5oz in 10m or less, so I am trying to figure out if she is getting her 3oz in such a short time and that's why she is full? She cluster feeds all evening though (3 week growth spurt?) which drives me nuts and we usually give her a bottle of pumped milk around 8 or 9 as I can't handle it anymore and she is acting starving and refusing the boob. I feel like she doesn't BF long enough though, and can't be getting the hind milk but I can't force her to drink more. Very frustrating. Not sure what to do.