When do I give up?

I want to exclusively breastfeed my daughter. I want it so bad. And it hurts my heart when she tugs at my breast with a sad squeal when the milk runs out and she’s still hungry. I have to feed her and I even though I pump 4-6 times a day on top of being at home with her and feeding we from the breast, I don’t have enough pumped milk to keep up. So then all I can do is pull out the formula. We’ve had a rough start. She’s almost 8 weeks old. She was born 3 weeks early with a weak such and a horrible tongue tie which led to awful latch issues. So we had to supplement right away and I was ok with that at first, thinking it was temporary. We’ve had weekly appointments with our lactation consultant and we’ve made progress. Her tongue had to be clipped twice now. She learned to latch with a shield and now she can latch without it (most of the time). We do suck training and tongue exercises and her suck is much stronger and she can get a lot more out of me than she ever could before. Her improved suck has led to a greater milk supply for me. I feel myself get fuller faster....but why is it not enough? Why do I still need about 6 oz of formula a day on top of all the milk I pump and bottle feed as well? I can’t keep up this pumping but I’ve been doing it since day 1 trying to increase my supply for her. I want to cry. My husband sees that I’m miserable and wants me to give up the pumping and just give her formula whenever. But I want to exclusively breastfeed. I want to be enough for my child. Will I ever get there? When do I give up?