Hi Hailie, thank you for reaching out. Your baby's gas could definitely be related to your letdown.
Try pumping off a little before feeding her. You could also try to lay back while feeding her, so that gravity is working with you to slow it down. Another trick is to put a little bit of pressure over your breast - essentially squishing it - so that the milk ducts are squished and the milk may flow a little slower. The pain that you're experiencing MAY go away or reduce in the next few weeks as your body adjusts to how much milk to make.
Hope this helps!
Beth

Hi Vanessa, thank you for reaching out! Are you also breastfeeding, or just pumping?
The pump flange may be too small, and/ or the pump may be set to strong. Try a larger flange and a softer suck and see if that helps!
Beth