Breast milk supply?

Amanda • Mother of two wonderful boys and a beautiful little girl.

So, my daughter is 7 weeks tomorrow.... She's gained literally just under a pound since birth.... I'm not sure if she's just not getting enough (which I believe she is cus she pees plenty!!) if the milk isn't giving her enough calories... If she's just nursing too long at a time (which I actually didn't know burns calories?!) or if the heart abnormality she has is causing her issues with weight gain... They're wanting me to pump and give her a bottle.... Basically measure how much she takes per feeding, and if she starts to gain a little weight.... Tbh, it put me deep in my head blaming myself, cus I feel like I should have caught on to her not gaining weight... And it's got me wondering if that's why she's so fussy all the time... She also spits up a lot too... If I even try to lay her down, she screams like she's in pain almost every time... I honestly feel like I'm failing her... I know it's not my fault.... I thought she was doing well, especially with how often she eats... Anyway... What are some things I can do to boost my supply? And maybe add calories to my supply possibly? Im trying so hard... Also, what's a good pump brand? I've got two wearable pumps, but they don't have the best suction... Any advice is appreciated