Losing Hope

Janelle
I really want to breastfeed!!! But I am not producing enough milk to satisfy my little one. She's 3wks. I've been to lactation for a weighed feeding. We determined my babe was only getting about 1.6 oz of breastmilk. I tried pumping between feedings and giving her anything I got extra (I only pump 1oz). She continued to be unsatisfied and was still not gaining ANY weight. Since she did not gain any weight in 1.5+ weeks and was in the 5th percentile, it was recommended we started supplementing. She seems to need an additional 2ozof formula on top of approx. 30 min of breastfeeding. This is exhausting. It takes nearly an hour and a half per session and next thing I know she's ready to eat again.
I've tried..
-offering each breast 2+ times 
-pumping right after feeding
-pumping between feedings
-drinking lots of water
-Gatorade
-oatmeal cookies
-Lactation bites (flaxseed, brewers yeast, oatmeal)
-boobie smoothies (similar ingredients)
-Mothers Milk Tea
-Fennegreek Pills
-formula first, then nursing 
I feel like there is nothing left to try. It's been a full week of supplementing and no increase in my supply. She STILL wants the 2oz extra. Now she has developed a bottle preference and sometimes fights me at the breast. Are my boobs broken?!!
I'm. Losing. Hope.