mommas I need help...

My daughter is 3 months and EBF. However lately it's like she's not getting enough. She eats for 5-10 minutes and then pulls off, latches back on and pulls off again maybe 5 or 6 times before she just throws a fit. I've tried upping my water, locations cookies and teas, and a milk supplement to help my supply but it's like NOTHING is working. I seriously feel like I'm failing and it breaks my heart. At night she seems to eat fine but during the day we have such a hard time. I'm at a loss and thinking about supplementing with formula, as much as I don't want to, I need my baby to eat. Does anyone have any tips about ANYTHING to do with breast feeding? I've tried pumping and only get 1-2 oz from both boobs combined.