Thinking about stopping BF 😭

My daughter is 4 months old and I cannot keep up with her appetite. I’ve been back to work for a month and my supply just keeps getting lower and lower. I power pump, drink tons of water, eat lactation snacks. And it’s just not helping. I pump for half an hour and get 3 ounces. She is eating four 5 ounce bottles during the time I am at work. We’ve been supplementing with formula, she’ll get 2 ounces of breastmilk and 3 ounces of formula. Even when I nurse her at home she’s never satisfied. This is such a tough decision for me.