Your letdown is too strong for her, she is getting too much foremilk and can't swallow it all, and since she's only getting foremilk, she's not being filled up and therefore hungry all the time.
Here is what you need to do. Latch her until your milkk lets down. When it does, unlatch her and catch the spray into a towel or a cup. When the spray slows or stops, relatch her and let her nurse. NURSE ONE SIDE ONLY! its an old wives tale that you need to switch sides, and its totally false. Let her nurse as long as she wants, until she pops off or falls asleep, on one breast only, then switch to the other side for the next feeding. I wore a stretchy bracelet on my wrist and just switched it from side to side to remember which breast to use at the next feeding.
She should be nursing from one breast only, this allows her the hindmilk that fills her up and also contains the fats and nutrients her body and brain need to grow and thrive. If you don't let her nurse during your letdown, it will signal your body to stop putting out such a forceful letdown, and it will slow.
Her poops should be yellow, soft, and seedy. If they are green and stringy, like wet lettuce, she is getting too much foremilk, and you need to unlatch her during your letdown spray, and relatch her when its done spraying.
Also, too much foremilk from a forceful letdown will make her gassy and really uncomfortable. So use hte method above for a few days and you will see a big difference. In a couple weeks your letdown will slow, and she will also be bigger to drink faster, and you won't have to use this method. But I encourage you to try it for a week before you switch to pumping. Pumping is a full itme job, and you will still have to bottle feed your baby, then pump, then bottle feed, then pump. Its like feeding two babies... know what I mean? Your issue is very common and easily fixable, so try what I suggested, you will notice a big difference. Send me a message if you need more info or support!